tcp: Remove unused tw_cookie_values from tcp_timewait_sock

tw_cookie_values is never used in the TCP-stack.

It was added by 435cf559 (TCPCT part 1d: define TCP cookie option,
extend existing struct's), but already at that time it was not used at
all, nor mentioned in the commit-message.
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/tcp.h

@@ -361,10 +361,6 @@ struct tcp_timewait_sock {
 #ifdef CONFIG_TCP_MD5SIG
 	struct tcp_md5sig_key	  *tw_md5_key;
 #endif
-	/* Few sockets in timewait have cookies; in that case, then this
-	 * object holds a reference to them (tw_cookie_values->kref).
-	 */
-	struct tcp_cookie_values  *tw_cookie_values;
 };
 
 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)