net: Remove the member netns_ok

Every protocol has the 'netns_ok' member and it is euqal to 1. The
'if (!prot->netns_ok)' always false in inet_add_protocol().

Signed-off-by: Yejune Deng <yejunedeng@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/protocol.c

@@ -1171,7 +1171,6 @@ static const struct net_protocol sctp_protocol = {
 	.handler     = sctp4_rcv,
 	.err_handler = sctp_v4_err,
 	.no_policy   = 1,
-	.netns_ok    = 1,
 	.icmp_strict_tag_validation = 1,
 };