netfilter: unregister nf hooks, matches and targets in the reverse order

Since we register nf hooks, matches and targets in order, we'd better
unregister them in the reverse order.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/core.c

@@ -105,10 +105,8 @@ EXPORT_SYMBOL(nf_register_hooks);
 
 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n)
 {
-	unsigned int i;
-
-	for (i = 0; i < n; i++)
-		nf_unregister_hook(&reg[i]);
+	while (n-- > 0)
+		nf_unregister_hook(&reg[n]);
 }
 EXPORT_SYMBOL(nf_unregister_hooks);
 

net/netfilter/x_tables.c

@@ -116,10 +116,8 @@ EXPORT_SYMBOL(xt_register_targets);
 void
 xt_unregister_targets(struct xt_target *target, unsigned int n)
 {
-	unsigned int i;
-
-	for (i = 0; i < n; i++)
-		xt_unregister_target(&target[i]);
+	while (n-- > 0)
+		xt_unregister_target(&target[n]);
 }
 EXPORT_SYMBOL(xt_unregister_targets);
 
@@ -174,10 +172,8 @@ EXPORT_SYMBOL(xt_register_matches);
 void
 xt_unregister_matches(struct xt_match *match, unsigned int n)
 {
-	unsigned int i;
-
-	for (i = 0; i < n; i++)
-		xt_unregister_match(&match[i]);
+	while (n-- > 0)
+		xt_unregister_match(&match[n]);
 }
 EXPORT_SYMBOL(xt_unregister_matches);