[PATCH v2] nbd: add missing definition of pr_fmt

[Yu Kuai]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

commit 1243172d5894 ("nbd: use pr_err to output error message") tries
to define pr_fmt and use short pr_err() to output error message,
however, the definition is missed.

This patch also remove existing "nbd:" inside pr_err().

Fixes: 1243172d5894 ("nbd: use pr_err to output error message")
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
Changes in v2, suggested by Joe
 - move pr_fmt() to before any #include, so that #undef can be remove
 - remove existing "nbd:"

 drivers/block/nbd.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index f5d098a148cb..2a709daefbc4 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -11,6 +11,8 @@
  * (part of code stolen from loop.c)
  */
 
+#define pr_fmt(fmt) "nbd: " fmt
+
 #include <linux/major.h>
 
 #include <linux/blkdev.h>
@@ -1950,7 +1952,7 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
 			     test_bit(NBD_DISCONNECT_REQUESTED, &nbd->flags)) ||
 			    !refcount_inc_not_zero(&nbd->refs)) {
 				mutex_unlock(&nbd_index_mutex);
-				pr_err("nbd: device at index %d is going down\n",
+				pr_err("device at index %d is going down\n",
 					index);
 				return -EINVAL;
 			}
@@ -1961,7 +1963,7 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
 	if (!nbd) {
 		nbd = nbd_dev_add(index, 2);
 		if (IS_ERR(nbd)) {
-			pr_err("nbd: failed to add new device\n");
+			pr_err("failed to add new device\n");
 			return PTR_ERR(nbd);
 		}
 	}
-- 
2.31.1