sched/core: Reuse put_prev_task()

Reuse put_prev_task() instead of copying its implementation.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Link: http://lkml.kernel.org/r/e2e50578223d05c5e90a9feb964fe1ec5d09a052.1495603536.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/core.c

@@ -5438,7 +5438,7 @@ static void migrate_tasks(struct rq *dead_rq, struct rq_flags *rf)
 		 */
 		next = pick_next_task(rq, &fake_task, rf);
 		BUG_ON(!next);
-		next->sched_class->put_prev_task(rq, next);
+		put_prev_task(rq, next);
 
 		/*
 		 * Rules for changing task_struct::cpus_allowed are holding