s390/block/scm_blk: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220232.1071926-7-mcgrof@kernel.orgSigned-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

drivers/s390/block/scm_blk.c

@@ -495,9 +495,14 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
 
 	/* 512 byte sectors */
 	set_capacity(bdev->gendisk, scmdev->size >> 9);
-	device_add_disk(&scmdev->dev, bdev->gendisk, NULL);
+	ret = device_add_disk(&scmdev->dev, bdev->gendisk, NULL);
+	if (ret)
+		goto out_cleanup_disk;
+
 	return 0;
 
+out_cleanup_disk:
+	blk_cleanup_disk(bdev->gendisk);
 out_tag:
 	blk_mq_free_tag_set(&bdev->tag_set);
 out: