netfilter: remove unnecessary goto statement for error recovery

Usually it's a good practice to use goto statement for error recovery
when initializing the module. This approach could be an overkill if:

 1) there is only one fail case;
 2) success and failure use the same return statement.

For a cleaner approach, remove the unnecessary goto statement and
directly implement error recovery.
Signed-off-by: NJean Sacren <sakiwit@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/ipv4/netfilter/iptable_filter.c

@@ -94,14 +94,10 @@ static int __init iptable_filter_init(void)
 	filter_ops = xt_hook_link(&packet_filter, iptable_filter_hook);
 	if (IS_ERR(filter_ops)) {
 		ret = PTR_ERR(filter_ops);
-		goto cleanup_table;
+		unregister_pernet_subsys(&iptable_filter_net_ops);
 	}
 
 	return ret;
-
- cleanup_table:
-	unregister_pernet_subsys(&iptable_filter_net_ops);
-	return ret;
 }
 
 static void __exit iptable_filter_fini(void)

net/ipv4/netfilter/iptable_mangle.c

@@ -129,14 +129,10 @@ static int __init iptable_mangle_init(void)
 	mangle_ops = xt_hook_link(&packet_mangler, iptable_mangle_hook);
 	if (IS_ERR(mangle_ops)) {
 		ret = PTR_ERR(mangle_ops);
-		goto cleanup_table;
+		unregister_pernet_subsys(&iptable_mangle_net_ops);
 	}
 
 	return ret;
-
- cleanup_table:
-	unregister_pernet_subsys(&iptable_mangle_net_ops);
-	return ret;
 }
 
 static void __exit iptable_mangle_fini(void)

net/ipv4/netfilter/iptable_raw.c

@@ -73,14 +73,10 @@ static int __init iptable_raw_init(void)
 	rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook);
 	if (IS_ERR(rawtable_ops)) {
 		ret = PTR_ERR(rawtable_ops);
-		goto cleanup_table;
+		unregister_pernet_subsys(&iptable_raw_net_ops);
 	}
 
 	return ret;
-
- cleanup_table:
-	unregister_pernet_subsys(&iptable_raw_net_ops);
-	return ret;
 }
 
 static void __exit iptable_raw_fini(void)