sched/smp: Use the SMP version of task_on_cpu()

Simplify the scheduler by making CONFIG_SMP=y code in task_on_cpu()
unconditional.

Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Shrikanth Hegde <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Vincent Guittot <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Ingo Molnar

kernel/sched/sched.h

@@ -2238,11 +2238,7 @@ static inline int task_current_donor(struct rq *rq, struct task_struct *p)
 
 static inline int task_on_cpu(struct rq *rq, struct task_struct *p)
 {
-#ifdef CONFIG_SMP
 	return p->on_cpu;
-#else
-	return task_current(rq, p);
-#endif
 }
 
 static inline int task_on_rq_queued(struct task_struct *p)