netfilter: xtables: mark initial tables constant

The inputted table is never modified, so should be considered const.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv4/netfilter/nf_nat_rule.c b/net/ipv4/netfilter/nf_nat_rule.c
index 6448a9b..9e81e0d 100644
--- a/net/ipv4/netfilter/nf_nat_rule.c
+++ b/net/ipv4/netfilter/nf_nat_rule.c
@@ -28,7 +28,7 @@
 			 (1 << NF_INET_POST_ROUTING) | \
 			 (1 << NF_INET_LOCAL_OUT))
 
-static struct
+static const struct
 {
 	struct ipt_replace repl;
 	struct ipt_standard entries[3];
@@ -58,7 +58,7 @@
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table nat_table = {
+static const struct xt_table nat_table = {
 	.name		= "nat",
 	.valid_hooks	= NAT_VALID_HOOKS,
 	.me		= THIS_MODULE,