rbd: delete an unnecessary check before rbd_dev_destroy()

Author: Markus Elfring <elfring@users.sourceforge.net>

The rbd_dev_destroy() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
Signed-off-by: Ilya Dryomov 
---
 drivers/block/rbd.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 81ea69f..4a87678 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5185,8 +5185,7 @@ static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
 
 out_err:
 	rbd_dev_unparent(rbd_dev);
-	if (parent)
-		rbd_dev_destroy(parent);
+	rbd_dev_destroy(parent);
 	return ret;
 }