perf hists: Fix hists_evsel to release hists

Since hists__init doesn't set the destructor of hists_evsel (which is an
extended evsel structure), when hists_evsel is released, the extended
part of the hists_evsel is not deleted (note that the hists_evsel object
itself is freed).

This fixes it to add a destructor for hists__evsel and to set it up.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20151209021129.10245.28710.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.c

@@ -1567,6 +1567,13 @@ static int hists_evsel__init(struct perf_evsel *evsel)
 	return 0;
 }
 
+static void hists_evsel__exit(struct perf_evsel *evsel)
+{
+	struct hists *hists = evsel__hists(evsel);
+
+	hists__delete_entries(hists);
+}
+
 /*
  * XXX We probably need a hists_evsel__exit() to free the hist_entries
  * stored in the rbtree...
@@ -1575,7 +1582,8 @@ static int hists_evsel__init(struct perf_evsel *evsel)
 int hists__init(void)
 {
 	int err = perf_evsel__object_config(sizeof(struct hists_evsel),
-					    hists_evsel__init, NULL);
+					    hists_evsel__init,
+					    hists_evsel__exit);
 	if (err)
 		fputs("FATAL ERROR: Couldn't setup hists class\n", stderr);