perf evlist: Add perf_evlist__remove()

perf evlist: Add perf_evlist__remove()

Add a counterpart to perf_evlist__add() that does the opposite and
deletes the evsel.

This will be used by perf inject to remove unwanted evsels.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-23-git-send-email-adrian.hunter@intel.com
[ Renamed it from perf_evlist__del() to perf_evlist__remove() and removed the perf_evsel__delete() call ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>