perf kmem: Fix segfault when invalid sort key is given
perf kmem: Fix segfault when invalid sort key is given

When it tries to free 'str', it was already updated by strsep() - so it
needs to save the original pointer.

  # perf kmem stat -s xxx,hit
    Error: Unknown --sort key: 'xxx'
  *** Error in `perf': free(): invalid pointer: 0x0000000000e9e7b6 ***
  ======= Backtrace: =========
  /usr/lib/libc.so.6(+0x7198e)[0x7fc7e6e0d98e]
  /usr/lib/libc.so.6(+0x76dee)[0x7fc7e6e12dee]
  /usr/lib/libc.so.6(+0x775cb)[0x7fc7e6e135cb]
  ./perf[0x44a1b5]
  ./perf[0x490b20]
  ./perf(parse_options_step+0x173)[0x491773]
  ./perf(parse_options_subcommand+0xa7)[0x491fb7]
  ./perf(cmd_kmem+0x2bc)[0x44ae4c]
  ./perf[0x47aa13]
  ./perf(main+0x60a)[0x427a9a]
  /usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7fc7e6dbc800]
  ./perf(_start+0x29)[0x427bb9]

Signed-off-by: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>
Cc: David Ahern <b80c1600f604d3b0d768f26f90a76757e76005dd@gmail.com>
Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@kernel.org>
Cc: Jiri Olsa <2c6594f608aa3d41e98d48846a6328831f7084ad@redhat.com>
Cc: Joonsoo Kim <d91a346a9a76eb1627d34d097d6cb4c8e5067100@gmail.com>
Cc: Minchan Kim <eee62f459f15dcddf87a8df69e8328e2a2562028@kernel.org>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Link: http://lkml.kernel.org/r/1426145571-3065-2-git-send-email-5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs