perf evsel: Fix a build failure on cross compilation

perf evsel: Fix a build failure on cross compilation

The commit c410431cefefd ("perf tools: Reconstruct event with modifiers
from perf_event_attr") added the line, but it's broken since it needs to
go up 3 directories to get to the kernel root directory, not 2.

However host gcc contains /usr/local/include in its search path, so that
it can find the perf_event.h in /usr/include. This why we didn't notice
the problem yet.  But when I tried to cross compile it appears like:

      CC util/evsel.o
  util/evsel.c:18:44: error: ../../include/linux/perf_event.h: No such file or directory
  make: *** [util/evsel.o] Error 1

Looking at the source, it isn't needed at all as evsel.h already
included the perf_event.h. So simply remove it would solve the problem.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340268772-5737-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>