sched: Fix rt_rq->pushable_tasks initialization in init_rt_rq()

init_rt_rq() initializes only rq->rt.pushable_tasks, and not the
pushable_tasks field of the passed rt_rq.  The plist is not used
uninitialized since the only pushable_tasks plists used are the
ones of root rt_rqs; anyway reinitializing the list on every group
creation corrupts the root plist, losing its previous contents.

Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090615185638.GK21741@gandalf.sssup.it>
CC: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index c4549bd..efecfda 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9093,7 +9093,7 @@
 #ifdef CONFIG_SMP
 	rt_rq->rt_nr_migratory = 0;
 	rt_rq->overloaded = 0;
-	plist_head_init(&rq->rt.pushable_tasks, &rq->lock);
+	plist_head_init(&rt_rq->pushable_tasks, &rq->lock);
 #endif
 
 	rt_rq->rt_time = 0;