ocfs2/net: fix uninitialized ret in o2net_send_message_vec()

mmotm/fs/ocfs2/cluster/tcp.c: In function ‘o2net_send_message_vec’:
mmotm/fs/ocfs2/cluster/tcp.c:980:6: warning: ‘ret’ may be used uninitialized in this function

It seems a real bug introduced by commit 9af0b38f (ocfs2/net:
Use wait_event() in o2net_send_message_vec()).

cc: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/cluster/tcp.c

@@ -977,7 +977,7 @@ static int o2net_tx_can_proceed(struct o2net_node *nn,
 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
 			   size_t caller_veclen, u8 target_node, int *status)
 {
-	int ret;
+	int ret = 0;
 	struct o2net_msg *msg = NULL;
 	size_t veclen, caller_bytes = 0;
 	struct kvec *vec = NULL;