blk-wbt: remove unnecessary check in wbt_enable_default()

If CONFIG_BLK_WBT_MQ is disabled, wbt_init() won't do anything.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019121518.3865235-3-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-wbt.c

@@ -651,7 +651,7 @@ void wbt_enable_default(struct request_queue *q)
 	if (!blk_queue_registered(q))
 		return;
 
-	if (queue_is_mq(q) && IS_ENABLED(CONFIG_BLK_WBT_MQ))
+	if (queue_is_mq(q))
 		wbt_init(q);
 }
 EXPORT_SYMBOL_GPL(wbt_enable_default);