netfilter: xtables: slightly better error reporting

When extended status codes are available, such as ENOMEM on failed
allocations, or subsequent functions (e.g. nf_ct_get_l3proto), passing
them up to userspace seems like a good idea compared to just always
EINVAL.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c
index 22b5b70..efcf56d 100644
--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -93,7 +93,7 @@
 
 	ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
 	if (!ledinternal)
-		return -EINVAL;
+		return -ENOMEM;
 
 	ledinternal->netfilter_led_trigger.name = ledinfo->id;
 
@@ -115,7 +115,7 @@
 
 exit_alloc:
 	kfree(ledinternal);
-	return -EINVAL;
+	return err;
 }
 
 static void led_tg_destroy(const struct xt_tgdtor_param *par)