[SIT]: Allow for IPPROTO_IPV6 protocol in namespaces.

This makes sit-generated traffic enter the namespace.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c
index cc4cd0e..d3b709a 100644
--- a/net/ipv4/tunnel4.c
+++ b/net/ipv4/tunnel4.c
@@ -144,6 +144,7 @@
 	.handler	=	tunnel64_rcv,
 	.err_handler	=	tunnel64_err,
 	.no_policy	=	1,
+	.netns_ok	=	1,
 };
 #endif