sched: hrtick_enabled() should use cpu_active()

Peter pointed out that hrtick_enabled() should use cpu_active().
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -1006,7 +1006,7 @@ static inline int hrtick_enabled(struct rq *rq)
 {
 	if (!sched_feat(HRTICK))
 		return 0;
-	if (!cpu_online(cpu_of(rq)))
+	if (!cpu_active(cpu_of(rq)))
 		return 0;
 	return hrtimer_is_hres_active(&rq->hrtick_timer);
 }