sched: Wrap scheduler p->cpus_allowed access

This task is preparatory for the migrate_disable() implementation, but
stands on its own and provides a cleanup.

It currently only converts those sites required for task-placement.
Kosaki-san once mentioned replacing cpus_allowed with a proper
cpumask_t instead of the NR_CPUS sized array it currently is, that
would also require something like this.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Link: http://lkml.kernel.org/n/tip-e42skvaddos99psip0vce41o@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 0cc188c..57a1084 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1179,7 +1179,7 @@
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
-	    (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) &&
+	    (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&
 	    (p->rt.nr_cpus_allowed > 1))
 		return 1;
 	return 0;
@@ -1324,7 +1324,7 @@
 			 */
 			if (unlikely(task_rq(task) != rq ||
 				     !cpumask_test_cpu(lowest_rq->cpu,
-						       &task->cpus_allowed) ||
+						       tsk_cpus_allowed(task)) ||
 				     task_running(rq, task) ||
 				     !task->on_rq)) {