perf unwind: Pass symbol source to libunwind
perf unwind: Pass symbol source to libunwind

Even if --symfs is used to point to the debug binaries, we send in the
non-debug filenames to libunwind, which leads to libunwind not finding
the debug frame.  Fix this by preferring the file in --symfs, if it is
available.

Signed-off-by: Rabin Vincent <b8c38523cce7640aaeed4045bf245272d3b467e3@axis.com>
Cc: Jiri Olsa <2c6594f608aa3d41e98d48846a6328831f7084ad@kernel.org>
Cc: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Cc: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Cc: Rabin Vincent <b2a546fd57f2f78e88a8ddb0e5c81b93ab234a54@axis.com>
Link: http://lkml.kernel.org/r/1446104978-26429-1-git-send-email-b8c38523cce7640aaeed4045bf245272d3b467e3@axis.com
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

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