tracing/ksym_tracer: fix the output of ksym tracer

Fix the output format of ksym tracer, make it properly aligned

Befor patch:
# tracer: ksym_tracer
#
#       TASK-PID      CPU#      Symbol         Type    Function
#          |           |          |              |         |
bash            1378  1   ksym_tracer_mutex     W  mutex_lock+0x11/0x27
bash            1378  1   ksym_filter_head      W  process_new_ksym_entry+0xd2/0x10c
bash            1378  1   ksym_tracer_mutex     W  mutex_unlock+0x12/0x1b
cat             1429  0   ksym_tracer_mutex     W  mutex_lock+0x11/0x27

After patch:
# tracer: ksym_tracer
#
#       TASK-PID   CPU#      Symbol                    Type    Function
#          |        |          |                        |         |
        cat-1423  [000] ksym_tracer_mutex               RW mutex_lock+0x11/0x27
        cat-1423  [000] ksym_filter_head                RW ksym_trace_filter_read+0x6e/0x10d
        cat-1423  [000] ksym_tracer_mutex               RW mutex_unlock+0x12/0x1b
        cat-1423  [000] ksym_tracer_mutex               RW mutex_lock+0x11/0x27
        cat-1423  [000] ksym_filter_head                RW ksym_trace_filter_read+0x6e/0x10d
        cat-1423  [000] ksym_tracer_mutex               RW mutex_unlock+0x12/0x1b

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
LKML-Reference: <4A6685BB.2090809@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>