sched/walt: don't requeue mvp task if only have one mvp task on rq

Don't requeue mvp task if only have one mvp task on rq, because
only have one mvp task on rq, current mvp task will be select for
running if this mvp task runtime still less than limit.

Change-Id: Idaf343e7471665c01fe711e86a3d7747e501ed76
Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>

kernel/sched/walt/walt_cfs.c

@@ -1127,6 +1127,9 @@ static void walt_cfs_account_mvp_runtime(struct rq *rq, struct task_struct *curr
 		return;
 	}
 
+	if (wrq->num_mvp_tasks == 1)
+		return;
+
 	/* slice expired. re-queue the task */
 	list_del(&wts->mvp_list);
 	wrq->num_mvp_tasks--;