genetlink: make all genl_ops users const

Now that genl_ops are no longer modified in place when
registering, they can be made const. This patch was done
mostly with spatch:

@@
identifier ops;
@@
+const
 struct genl_ops ops[] = {
 ...
 };

(except the struct thing in net/openvswitch/datapath.c)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index be446d5..57db66e 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -793,7 +793,7 @@
 	},
 };
 
-static struct genl_ops l2tp_nl_ops[] = {
+static const struct genl_ops l2tp_nl_ops[] = {
 	{
 		.cmd = L2TP_CMD_NOOP,
 		.doit = l2tp_nl_cmd_noop,