perf script: Pad DSO name for --call-trace

Pad the DSO name in --call-trace so we don't have the indent screwed by
different DSO name lengths, as now for kernel there's also BPF code
displayed.

  # perf-with-kcore record pt -e intel_pt//ku -- sleep 1
  # perf-core/perf-with-kcore script pt --call-trace

Before:

   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms])                      kretprobe_perf_func
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms])                          trace_call_bpf
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms])                              __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms])                                  __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464725: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_get_current_pid_tgid
   sleep 3660 [16] 57036.806464725: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_ktime_get_ns
   sleep 3660 [16] 57036.806464725: ([kernel.kallsyms])                                          __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464725: ([kernel.kallsyms])                                              __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806465045: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         __htab_map_lookup_elem
   sleep 3660 [16] 57036.806465366: ([kernel.kallsyms])                                          memcmp
   sleep 3660 [16] 57036.806465687: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_probe_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                          probe_kernel_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                              __check_object_size
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                                  check_stack_object
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                              copy_user_enhanced_fast_string
   sleep 3660 [16] 57036.806465687: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_probe_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                          probe_kernel_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                              __check_object_size
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                                  check_stack_object
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms])                                              copy_user_enhanced_fast_string
   sleep 3660 [16] 57036.806466008: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_get_current_uid_gid
   sleep 3660 [16] 57036.806466008: ([kernel.kallsyms])                                          from_kgid
   sleep 3660 [16] 57036.806466008: ([kernel.kallsyms])                                          from_kuid
   sleep 3660 [16] 57036.806466008: (bpf_prog_da4fe6b3d2c29b25_trace_return)                                         bpf_perf_event_output
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms])                                          perf_event_output
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms])                                              perf_prepare_sample
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms])                                                  perf_misc_flags
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms])                                                      __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms])                                                          __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806466328: ([kvm])                                                      kvm_is_in_guest
   sleep 3660 [16] 57036.806466649: ([kernel.kallsyms])                                                  __perf_event_header__init_id.isra.0
   sleep 3660 [16] 57036.806466649: ([kernel.kallsyms])                                              perf_output_begin

After:

   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms]                      )     kretprobe_perf_func
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms]                      )         trace_call_bpf
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms]                      )             __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464404: ([kernel.kallsyms]                      )                 __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464725: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_get_current_pid_tgid
   sleep 3660 [16] 57036.806464725: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_ktime_get_ns
   sleep 3660 [16] 57036.806464725: ([kernel.kallsyms]                      )                         __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806464725: ([kernel.kallsyms]                      )                             __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806465045: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     __htab_map_lookup_elem
   sleep 3660 [16] 57036.806465366: ([kernel.kallsyms]                      )                         memcmp
   sleep 3660 [16] 57036.806465687: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_probe_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                         probe_kernel_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                             __check_object_size
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                                 check_stack_object
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                             copy_user_enhanced_fast_string
   sleep 3660 [16] 57036.806465687: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_probe_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                         probe_kernel_read
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                             __check_object_size
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                                 check_stack_object
   sleep 3660 [16] 57036.806465687: ([kernel.kallsyms]                      )                             copy_user_enhanced_fast_string
   sleep 3660 [16] 57036.806466008: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_get_current_uid_gid
   sleep 3660 [16] 57036.806466008: ([kernel.kallsyms]                      )                         from_kgid
   sleep 3660 [16] 57036.806466008: ([kernel.kallsyms]                      )                         from_kuid
   sleep 3660 [16] 57036.806466008: (bpf_prog_da4fe6b3d2c29b25_trace_return )                     bpf_perf_event_output
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms]                      )                         perf_event_output
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms]                      )                             perf_prepare_sample
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms]                      )                                 perf_misc_flags
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms]                      )                                     __x86_indirect_thunk_rax
   sleep 3660 [16] 57036.806466328: ([kernel.kallsyms]                      )                                         __x86_indirect_thunk_rax

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190508132010.14512-8-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>