syncookies: fix inclusion of tcp options in syn-ack

David Miller noticed that commit
33ad798c '(tcp: options clean up')
did not move the req->cookie_ts check.
This essentially disabled commit 4dfc2817
'[Syncookies]: Add support for TCP options via timestamps.'.

This restores the original logic.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_output.c

@@ -2279,6 +2279,11 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	}
 
 	memset(&opts, 0, sizeof(opts));
+#ifdef CONFIG_SYN_COOKIES
+	if (unlikely(req->cookie_ts))
+		TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
+	else
+#endif
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
 	tcp_header_size = tcp_synack_options(sk, req, mss,
 					     skb, &opts, &md5) +
@@ -2304,11 +2309,6 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
 	/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
 	th->window = htons(min(req->rcv_wnd, 65535U));
-#ifdef CONFIG_SYN_COOKIES
-	if (unlikely(req->cookie_ts))
-		TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
-	else
-#endif
 	tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
 	th->doff = (tcp_header_size >> 2);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);