[NETLINK]: Mark netlink policies const

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 6e31234..b9ab62f 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -472,7 +472,7 @@
 	return skb;
 }
 
-static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = {
+static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
 	[CTRL_ATTR_FAMILY_ID]	= { .type = NLA_U16 },
 	[CTRL_ATTR_FAMILY_NAME]	= { .type = NLA_NUL_STRING,
 				    .len = GENL_NAMSIZ - 1 },