rbd: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO

Author: Duan Jiong <duanj.fnst@cn.fujitsu.com>

This patch fixes coccinelle error regarding usage of IS_ERR and
PTR_ERR instead of PTR_ERR_OR_ZERO.

Signed-off-by: Duan Jiong 
Reviewed-by: Yan, Zheng 
---
 drivers/block/rbd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4c95b50..552a2ed 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4752,7 +4752,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
 
 		image_id = ceph_extract_encoded_string(&p, p + ret,
 						NULL, GFP_NOIO);
-		ret = IS_ERR(image_id) ? PTR_ERR(image_id) : 0;
+		ret = PTR_ERR_OR_ZERO(image_id);
 		if (!ret)
 			rbd_dev->image_format = 2;
 	} else {