[IPV6] NETNS: Handle ancillary data in appropriate namespace.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 47123bf..1b35c47 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -731,7 +731,7 @@
 		memset(opt, 0, sizeof(struct ipv6_txoptions));
 		opt->tot_len = sizeof(*opt);
 
-		err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass);
+		err = datagram_send_ctl(sock_net(sk), msg, &fl, opt, &hlimit, &tclass);
 		if (err < 0) {
 			fl6_sock_release(flowlabel);
 			return err;