af_key: initialize xfrm encap_oa

Currently encap_oa is left uninitialized, so it contains garbage data which
is visible to userland via Netlink. Initialize it by zeroing it out.
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/key/af_key.c

@@ -1285,6 +1285,7 @@ static struct xfrm_state * pfkey_msg2xfrm_state(struct net *net,
 				ext_hdrs[SADB_X_EXT_NAT_T_DPORT-1];
 			natt->encap_dport = n_port->sadb_x_nat_t_port_port;
 		}
+		memset(&natt->encap_oa, 0, sizeof(natt->encap_oa));
 	}
 
 	err = xfrm_init_state(x);