perf tests x86: Fix memory leak in sample_ustack()
perf tests x86: Fix memory leak in sample_ustack()

The buf is not freed, when kernel failed to get stack map
and return.

Signed-off-by: Masanari Iida <f31bb8ac2957d045575b3081e813605474613a21@gmail.com>
Link: http://lkml.kernel.org/r/1398091024-7901-1-git-send-email-f31bb8ac2957d045575b3081e813605474613a21@gmail.com
Signed-off-by: Jiri Olsa <2c6594f608aa3d41e98d48846a6328831f7084ad@redhat.com>

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