appletalk: fix atalk_getname() leak

atalk_getname() can leak 8 bytes of kernel memory to user
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/appletalk/ddp.c

@@ -1237,6 +1237,7 @@ static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
 			return -ENOBUFS;
 
 	*uaddr_len = sizeof(struct sockaddr_at);
+	memset(&sat.sat_zero, 0, sizeof(sat.sat_zero));
 
 	if (peer) {
 		if (sk->sk_state != TCP_ESTABLISHED)