sched: Use task_current() instead of 'rq->curr == p'

Use the task_current() function where appropriate.

No functional change.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030173223.GA52339@rlk

kernel/sched/rt.c

@@ -2357,7 +2357,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 	if (!task_on_rq_queued(p))
 		return;
 
-	if (rq->curr == p) {
+	if (task_current(rq, p)) {
 #ifdef CONFIG_SMP
 		/*
 		 * If our priority decreases while running, we