cdrom_open() forgets to unlock on -EROFS failure exits

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 67ee3d4..79245714 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -1032,6 +1032,10 @@
 	check_disk_change(ip->i_bdev);
 	return 0;
 err_release:
+	if (CDROM_CAN(CDC_LOCK) && cdi->options & CDO_LOCK) {
+		cdi->ops->lock_door(cdi, 0);
+		cdinfo(CD_OPEN, "door unlocked.\n");
+	}
 	cdi->ops->release(cdi);
 err:
 	cdi->use_count--;