sched/fair: Use time_after() in record_wakee()

To be future-proof and for better readability the time comparisons are modified
to use time_after() instead of plain, error-prone math.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1400780723-24626-1-git-send-email-manuel.schoelling@gmx.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -4066,7 +4066,7 @@ static void record_wakee(struct task_struct *p)
 	 * about the boundary, really active task won't care
 	 * about the loss.
 	 */
-	if (jiffies > current->wakee_flip_decay_ts + HZ) {
+	if (time_after(jiffies, current->wakee_flip_decay_ts + HZ)) {
 		current->wakee_flips >>= 1;
 		current->wakee_flip_decay_ts = jiffies;
 	}