block: get rid of unnecessary local variable

Since whole elevator register is protectd by sysfs_lock, we
don't need extras 'has_elevator'. Just use q->elevator directly.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-sysfs.c

@@ -833,7 +833,6 @@ int blk_register_queue(struct gendisk *disk)
 	int ret;
 	struct device *dev = disk_to_dev(disk);
 	struct request_queue *q = disk->queue;
-	bool has_elevator = false;
 
 	if (WARN_ON(!q))
 		return -ENXIO;
@@ -899,7 +898,6 @@ int blk_register_queue(struct gendisk *disk)
 			kobject_put(&dev->kobj);
 			return ret;
 		}
-		has_elevator = true;
 	}
 
 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
@@ -908,7 +906,7 @@ int blk_register_queue(struct gendisk *disk)
 
 	/* Now everything is ready and send out KOBJ_ADD uevent */
 	kobject_uevent(&q->kobj, KOBJ_ADD);
-	if (has_elevator)
+	if (q->elevator)
 		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 	mutex_unlock(&q->sysfs_lock);