scsi: sr: Fix sr_probe() missing deallocate of device minor

[ Upstream commit 6555781b3fdec5e94e6914511496144241df7dee ]

If the cdrom fails to be registered then the device minor should be
deallocated.

Link: https://lore.kernel.org/r/072dac4b-8402-4de8-36bd-47e7588969cd@0882a8b5-c6c3-11e9-b005-00805fc181fe
Signed-off-by: Simon Arlott <simon@octiron.net>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: I1c4963228f90367230bbc466d2fb20fdb3954cd5
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index ff243f8..24255422 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -738,7 +738,7 @@
 	cd->cdi.disk = disk;
 
 	if (register_cdrom(&cd->cdi))
-		goto fail_put;
+		goto fail_minor;
 
 	/*
 	 * Initialize block layer runtime PM stuffs before the
@@ -756,6 +756,10 @@
 
 	return 0;
 
+fail_minor:
+	spin_lock(&sr_index_lock);
+	clear_bit(minor, sr_index_bits);
+	spin_unlock(&sr_index_lock);
 fail_put:
 	put_disk(disk);
 fail_free: