block: Remove unnecessary variable assignment

The parameter "ret" should be zero when running to this line,
no need to set to zero again, remove it.
Signed-off-by: GuoYong Zheng <zhenggy@chinatelecom.cn>
Link: https://lore.kernel.org/r/1642414957-6785-1-git-send-email-zhenggy@chinatelecom.cnSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-sysfs.c

@@ -887,7 +887,6 @@ int blk_register_queue(struct gendisk *disk)
 		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 	mutex_unlock(&q->sysfs_lock);
 
-	ret = 0;
 unlock:
 	mutex_unlock(&q->sysfs_dir_lock);