[added to the 4.1 stable tree] bcache: unregister reboot notifier if bcache fails to unregister device

From: Zheng Liu <redacted>

This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit 2ecf0cdb2b437402110ab57546e02abfa68a716b ]

In bcache_init() function it forgot to unregister reboot notifier if
bcache fails to unregister a block device.  This commit fixes this.

Signed-off-by: Zheng Liu <redacted>
Tested-by: Joshua Schmid <redacted>
Tested-by: Eric Wheeler <redacted>
Cc: Kent Overstreet <redacted>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <redacted>
---
 drivers/md/bcache/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 9d7b6ee..53f1512 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c

@@ -2105,8 +2105,10 @@ static int __init bcache_init(void)
 	closure_debug_init();
 
 	bcache_major = register_blkdev(0, "bcache");
-	if (bcache_major < 0)
+	if (bcache_major < 0) {
+		unregister_reboot_notifier(&reboot);
 		return bcache_major;
+	}
 
 	if (!(bcache_wq = create_workqueue("bcache")) ||
 	    !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||

-- 
2.5.0