tcp: add init_cookie_seq method to tcp_request_sock_ops

Move the specific IPv4/IPv6 cookie sequence initialization to a new
method in tcp_request_sock_ops in preparation for unifying
tcp_v4_conn_request and tcp_v6_conn_request.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 87a360c..17710cf 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -761,6 +761,9 @@
 	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
 #endif
 	.init_req	=	tcp_v6_init_req,
+#ifdef CONFIG_SYN_COOKIES
+	.cookie_init_seq =	cookie_v6_init_sequence,
+#endif
 };
 
 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
@@ -1061,7 +1064,7 @@
 
 	if (!isn) {
 		if (want_cookie) {
-			isn = cookie_v6_init_sequence(sk, skb, &req->mss);
+			isn = cookie_init_sequence(af_ops, sk, skb, &req->mss);
 			req->cookie_ts = tmp_opt.tstamp_ok;
 			goto have_isn;
 		}