[TCP]: Remove dead code in init_sequence

This removes two redundancies:

1) The test (skb->protocol == htons(ETH_P_IPV6) in tcp_v6_init_sequence()
   is always true, due to
	* tcp_v6_conn_request() is the only function calling this one
	* tcp_v6_conn_request() redirects all skb's with ETH_P_IP protocol to
	  tcp_v4_conn_request() [ cf. top of tcp_v6_conn_request()]

2) The first argument, `struct sock *sk' of tcp_v{4,6}_init_sequence() is
   never used.

Signed-off-by: Gerrit Renker  <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5fbf965..2eb5884 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -111,7 +111,7 @@
 	inet_unhash(&tcp_hashinfo, sk);
 }
 
-static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
+static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
 {
 	return secure_tcp_sequence_number(skb->nh.iph->daddr,
 					  skb->nh.iph->saddr,
@@ -859,7 +859,7 @@
 			goto drop_and_free;
 		}
 
-		isn = tcp_v4_init_sequence(sk, skb);
+		isn = tcp_v4_init_sequence(skb);
 	}
 	tcp_rsk(req)->snt_isn = isn;