net: constify remaining proto_ops

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c
index e0f9219..cc394d0 100644
--- a/drivers/net/pppol2tp.c
+++ b/drivers/net/pppol2tp.c
@@ -229,7 +229,7 @@
 static atomic_t pppol2tp_tunnel_count;
 static atomic_t pppol2tp_session_count;
 static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL };
-static struct proto_ops pppol2tp_ops;
+static const struct proto_ops pppol2tp_ops;
 
 /* per-net private data for this module */
 static int pppol2tp_net_id;
@@ -2574,7 +2574,7 @@
  * Init and cleanup
  *****************************************************************************/
 
-static struct proto_ops pppol2tp_ops = {
+static const struct proto_ops pppol2tp_ops = {
 	.family		= AF_PPPOX,
 	.owner		= THIS_MODULE,
 	.release	= pppol2tp_release,