perf evlist: Add perf_evlist__id2evsel_strict()

perf evlist: Add perf_evlist__id2evsel_strict()

perf_evlist__id2evsel_strict() is the same as perf_evlist__id2evsel()
except that it ensures that the id must match.

This will be used by perf inject to find a specific evsel that is to be
deleted, hence the need to match exactly.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-22-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>