perf evlist: Change evlist__splice_list_tail() ordering

Function find_evsel_group() expects events to be ordered such that they
are grouped after their leader.

Modify evlist__splice_list_tail() to guarantee this (ordering).

[Should prob also change the function name]
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Kajol Jain <kjain@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1607080216-36968-6-git-send-email-john.garry@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evlist.c

@@ -179,11 +179,22 @@ void evlist__remove(struct evlist *evlist, struct evsel *evsel)
 
 void evlist__splice_list_tail(struct evlist *evlist, struct list_head *list)
 {
-	struct evsel *evsel, *temp;
+	while (!list_empty(list)) {
+		struct evsel *evsel, *temp, *leader = NULL;
 
-	__evlist__for_each_entry_safe(list, temp, evsel) {
-		list_del_init(&evsel->core.node);
-		evlist__add(evlist, evsel);
+		__evlist__for_each_entry_safe(list, temp, evsel) {
+			list_del_init(&evsel->core.node);
+			evlist__add(evlist, evsel);
+			leader = evsel;
+			break;
+		}
+
+		__evlist__for_each_entry_safe(list, temp, evsel) {
+			if (evsel->leader == leader) {
+				list_del_init(&evsel->core.node);
+				evlist__add(evlist, evsel);
+			}
+		}
 	}
 }