net: mark net_proto_ops as const

All usages of structure net_proto_ops should be declared const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index f60c0c2..c711d58 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -118,7 +118,7 @@
 	return err;
 }
 
-static struct net_proto_family phonet_proto_family = {
+static const struct net_proto_family phonet_proto_family = {
 	.family = PF_PHONET,
 	.create = pn_socket_create,
 	.owner = THIS_MODULE,