net: netlink_getname, packet_getname -- use DECLARE_SOCKADDR guard

Use guard DECLARE_SOCKADDR in a few more places which allow
us to catch if the structure copied back is too big.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 3304caa..c620bd9 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1537,7 +1537,7 @@
 	struct net_device *dev;
 	struct sock *sk = sock->sk;
 	struct packet_sock *po = pkt_sk(sk);
-	struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
+	DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
 
 	if (peer)
 		return -EOPNOTSUPP;