sched/fair: Fix endless loop in idle_balance()

Check for fair tasks number to decide, that we've pulled a task.
rq's nr_running may contain throttled RT tasks.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394118975.19290.104.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -6710,7 +6710,7 @@ static int idle_balance(struct rq *this_rq)
 	 * While browsing the domains, we released the rq lock.
 	 * A task could have be enqueued in the meantime
 	 */
-	if (this_rq->nr_running && !pulled_task) {
+	if (this_rq->cfs.h_nr_running && !pulled_task) {
 		pulled_task = 1;
 		goto out;
 	}