Revert "block: call bdput() to avoid memleak"

hulk inclusion
category: bugfix
bugzilla: 55097
CVE: NA

-------------------------------------------------

This reverts commit d6dd218d.

The patch set for partition symlink cleanup will introduce
deadlock for nbd, loop and xen-blkfront driver, so revert it.
Signed-off-by: NHou Tao <houtao1@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

block/genhd.c

@@ -792,10 +792,8 @@ void del_gendisk(struct gendisk *disk)
 		delete_partition(disk, part->partno);
 	}
 	disk_part_iter_exit(&piter);
-	if (bdev) {
+	if (bdev)
 		mutex_unlock(&bdev->bd_mutex);
-		bdput(bdev);
-	}
 
 	invalidate_partition(disk, 0);
 	bdev_unhash_inode(disk_devt(disk));