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/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index d3ee2e0..8c121b5 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -991,7 +991,7 @@
 	return 0;
 }
 
-static struct genl_ops tcp_metrics_nl_ops[] = {
+static const struct genl_ops tcp_metrics_nl_ops[] = {
 	{
 		.cmd = TCP_METRICS_CMD_GET,
 		.doit = tcp_metrics_nl_cmd_get,