sched/deadline: Fix dl_server_stopped()

Commit cccb45d ("sched/deadline: Less agressive dl_server handling")
introduces dl_server_stopped(). But it is obvious that dl_server_stopped()
should return true if dl_se->dl_server_active is 0.

Fixes: cccb45d ("sched/deadline: Less agressive dl_server handling")
Signed-off-by: Huacai Chen <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

Author: chenhuacai

kernel/sched/deadline.c

@@ -1611,7 +1611,7 @@ void dl_server_stop(struct sched_dl_entity *dl_se)
 static bool dl_server_stopped(struct sched_dl_entity *dl_se)
 {
 	if (!dl_se->dl_server_active)
-		return false;
+		return true;
 
 	if (dl_se->dl_server_idle) {
 		dl_server_stop(dl_se);