dcbnl: Silence harmless gcc warning about uninitialized reply_nlh

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 70bba3e..da6ee81 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1664,7 +1664,7 @@
 	u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 	int ret = -EINVAL;
 	struct sk_buff *reply_skb;
-	struct nlmsghdr *reply_nlh;
+	struct nlmsghdr *reply_nlh = NULL;
 	const struct reply_func *fn;
 
 	if (!net_eq(net, &init_net))