sched: wakeup preemption fix

wakeup preemption fix: do not make it dependent on p->prio.
Preemption purely depends on ->vruntime.

This improves preemption in mixed-nice-level workloads.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched_fair.c

@@ -863,10 +863,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
 		if (unlikely(se->load.weight != NICE_0_LOAD))
 			gran = calc_delta_fair(gran, &se->load);
 
-		if (delta > gran) {
-			if (p->prio < curr->prio)
-				resched_task(curr);
-		}
+		if (delta > gran)
+			resched_task(curr);
 	}
 }