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/ipx/af_ipx.c b/net/ipx/af_ipx.c
index 66c7a20..6481ee4 100644
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1927,7 +1927,7 @@
  * Socket family declarations
  */
 
-static struct net_proto_family ipx_family_ops = {
+static const struct net_proto_family ipx_family_ops = {
 	.family		= PF_IPX,
 	.create		= ipx_create,
 	.owner		= THIS_MODULE,