ipcomp: Mark as netns_ok.

This module is namespace aware, netns_ok was just disabled by default
for sanity.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ipcomp.c

@@ -163,6 +163,7 @@ static const struct net_protocol ipcomp4_protocol = {
 	.handler	=	xfrm4_rcv,
 	.err_handler	=	ipcomp4_err,
 	.no_policy	=	1,
+	.netns_ok	=	1,
 };
 
 static int __init ipcomp4_init(void)