sched/core: Simplify sched_class::pick_next_task()

Now that the indirect class call never uses the last two arguments of
pick_next_task(), remove them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: ktkhai@virtuozzo.com
Cc: mgorman@suse.de
Cc: qais.yousef@arm.com
Cc: qperret@google.com
Cc: rostedt@goodmis.org
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Link: https://lkml.kernel.org/r/20191108131909.660595546@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7cf6547..513a479 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3924,7 +3924,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 		/* Assumes fair_sched_class->next == idle_sched_class */
 		if (!p) {
 			put_prev_task(rq, prev);
-			p = pick_next_task_idle(rq, NULL, NULL);
+			p = pick_next_task_idle(rq);
 		}
 
 		return p;
@@ -3949,7 +3949,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	put_prev_task(rq, prev);
 
 	for_each_class(class) {
-		p = class->pick_next_task(rq, NULL, NULL);
+		p = class->pick_next_task(rq);
 		if (p)
 			return p;
 	}
@@ -6210,7 +6210,7 @@ static struct task_struct *__pick_migrate_task(struct rq *rq)
 	struct task_struct *next;
 
 	for_each_class(class) {
-		next = class->pick_next_task(rq, NULL, NULL);
+		next = class->pick_next_task(rq);
 		if (next) {
 			next->sched_class->put_prev_task(rq, next);
 			return next;