perf probe: Fix to free temporal Dwarf_Frame

Since dwarf_cfi_addrframe returns malloc'd Dwarf_Frame object, it has to
be freed after it is used.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20151118064011.30709.65674.stgit@localhost.localdomain


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