[NETNS][IPV6] tcp - assign the netns for timewait sockets

Copy the network namespace from the socket to the timewait socket.
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/inet_timewait_sock.c

@@ -124,6 +124,7 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
 		tw->tw_hash	    = sk->sk_hash;
 		tw->tw_ipv6only	    = 0;
 		tw->tw_prot	    = sk->sk_prot_creator;
+		tw->tw_net          = sk->sk_net;
 		atomic_set(&tw->tw_refcnt, 1);
 		inet_twsk_dead_node_init(tw);
 		__module_get(tw->tw_prot->owner);