[SCSI] bsg: fix bsg_unregister_queue

scsi_sysfs_add_sdev ignores the bsg_register_queue failure, so
bsg_unregister_queue must check whether the queue has a bsg device.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/block/bsg.c b/block/bsg.c
index 4eebcd5c7311..1ba9bc6d9a44 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -932,7 +932,8 @@ void bsg_unregister_queue(struct request_queue *q)
 {
         struct bsg_class_device *bcd = &q->bsg_dev;
 
-        WARN_ON(!bcd->class_dev);
+        if (!bcd->class_dev)
+                return;
 
         mutex_lock(&bsg_mutex);
         sysfs_remove_link(&q->kobj, "bsg");