perf/core: Remove perf_event::group_entry

Now that all the grouping is done with RB trees, we no longer need
group_entry and can replace the whole thing with sibling_list.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/sparc/kernel/perf_event.c

@@ -1342,7 +1342,7 @@ static int collect_events(struct perf_event *group, int max_count,
 		events[n] = group->hw.event_base;
 		current_idx[n++] = PIC_NO_INDEX;
 	}
-	list_for_each_entry(event, &group->sibling_list, group_entry) {
+	list_for_each_entry(event, &group->sibling_list, sibling_list) {
 		if (!is_software_event(event) &&
 		    event->state != PERF_EVENT_STATE_OFF) {
 			if (n >= max_count)