[IPV6]: Do not change protocol for raw IPv6 sockets.

It is not allowed to change underlying protocol for
   int fd = socket(PF_INET6, SOCK_RAW, IPPROTO_UDP);
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

net/ipv6/ipv6_sockglue.c

@@ -161,6 +161,9 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 			struct ipv6_txoptions *opt;
 			struct sk_buff *pktopt;
 
+			if (sk->sk_type == SOCK_RAW)
+				break;
+
 			if (sk->sk_protocol != IPPROTO_UDP &&
 			    sk->sk_protocol != IPPROTO_UDPLITE &&
 			    sk->sk_protocol != IPPROTO_TCP)