[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/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index fc3882c..53b3998 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -157,7 +157,7 @@
 	return 1;
 }
 
-static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
+static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
 	FRA_GENERIC_POLICY,
 };