sched: Refine the code in unthrottle_cfs_rq()

Directly use rq to save some code.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51AD87EB.1070605@linux.vnet.ibm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -2315,7 +2315,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	int enqueue = 1;
 	long task_delta;
 
-	se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
+	se = cfs_rq->tg->se[cpu_of(rq)];
 
 	cfs_rq->throttled = 0;