sched: reorder update_cpu_load(rq) with the ->task_tick() call

Peter Williams suggested to flip the order of update_cpu_load(rq) with
the ->task_tick() call. This is a NOP for the current scheduler (the
two functions are independent of each other), ->task_tick() might
create some state for update_cpu_load() in the future (or in PlugSched).
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -3298,9 +3298,9 @@ void scheduler_tick(void)
 	struct task_struct *curr = rq->curr;
 
 	spin_lock(&rq->lock);
+	update_cpu_load(rq);
 	if (curr != rq->idle) /* FIXME: needed? */
 		curr->sched_class->task_tick(rq, curr);
-	update_cpu_load(rq);
 	spin_unlock(&rq->lock);
 
 #ifdef CONFIG_SMP