perf: Ignore perf.data.old

Tell git to ignore this file.

Signed-off-by: WANG Cong <amwang@redhat.com>
LKML-Reference: <20100125051052.3999.28082.sendpatchset@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed