If the shared_buffer allocation fails, need to unregister mgmt_dev first.

Fixes: abebb16254b36 ("vdpa_sim_blk: support shared backend")
Signed-off-by: Shawn.Shao <shawn.shao@jaguarmicro.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
index 00d7d72713be..b3a3cb165795 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -499,12 +499,13 @@ static int __init vdpasim_blk_init(void)
 					 GFP_KERNEL);
 		if (!shared_buffer) {
 			ret = -ENOMEM;
-			goto parent_err;
+			goto mgmt_dev_err;
 		}
 	}
 
 	return 0;
-
+mgmt_dev_err:
+	vdpa_mgmtdev_unregister(&mgmt_dev);
 parent_err:
 	device_unregister(&vdpasim_blk_mgmtdev);
 	return ret;
-- 
2.34.1