ipv6: tcp: clean up tcp_v6_early_demux() icsk variable

Remove an icsk variable, which by convention should refer to an
inet_connection_sock rather than an inet_sock. In the process, make
the tcp_v6_early_demux() code and formatting a bit more like
tcp_v4_early_demux(), to ease comparisons and maintenance.
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/tcp_ipv6.c

@@ -1741,11 +1741,11 @@ static void tcp_v6_early_demux(struct sk_buff *skb)
 		skb->destructor = sock_edemux;
 		if (sk->sk_state != TCP_TIME_WAIT) {
 			struct dst_entry *dst = sk->sk_rx_dst;
-			struct inet_sock *icsk = inet_sk(sk);
+
 			if (dst)
 				dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
 			if (dst &&
-			    icsk->rx_dst_ifindex == skb->skb_iif)
+			    inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
 				skb_dst_set_noref(skb, dst);
 		}
 	}