[PATCH] nbd: fix uninitialized variable warning

[pannengyuan]

From: Pan Nengyuan <pannengy...@huawei.com>

Fixes:
/mnt/sdb/qemu/nbd/server.c: In function 'nbd_handle_request':
/mnt/sdb/qemu/nbd/server.c:2313:9: error: 'ret' may be used uninitialized in 
this function [-Werror=maybe-uninitialized]
     int ret;

Reported-by: Euler Robot <euler.ro...@huawei.com>
Signed-off-by: Pan Nengyuan <pannengy...@huawei.com>
---
 nbd/server.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nbd/server.c b/nbd/server.c
index 24ebc1a805..7eb3de0842 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2310,7 +2310,7 @@ static coroutine_fn int nbd_handle_request(NBDClient 
*client,
                                            NBDRequest *request,
                                            uint8_t *data, Error **errp)
 {
-    int ret;
+    int ret = 0;
     int flags;
     NBDExport *exp = client->exp;
     char *msg;
-- 
2.21.0.windows.1