invoice_hook: remove nested result.

I misunderstood the API, this ended up nesting a result inside the JSON-RPC
result.

No concerns about backwards compatibility since this is so new.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/invoice.c

@@ -141,23 +141,17 @@ static bool hook_gives_failcode(const char *buffer,
 				const jsmntok_t *toks,
 				enum onion_type *failcode)
 {
-	const jsmntok_t *resulttok, *t;
+	const jsmntok_t *t;
 	unsigned int val;
 
 	/* No plugin registered on hook at all? */
 	if (!buffer)
 		return false;
 
-	resulttok = json_get_member(buffer, toks, "result");
-	if (!resulttok)
-		fatal("Invalid invoice_payment_hook response: %.*s",
-		      toks[0].end - toks[1].start, buffer);
-
-	t = json_get_member(buffer, resulttok, "failure_code");
+	t = json_get_member(buffer, toks, "failure_code");
 	if (!t)
 		return false;
 
-
 	if (!json_to_number(buffer, t, &val))
 		fatal("Invalid invoice_payment_hook failure_code: %.*s",
 		      toks[0].end - toks[1].start, buffer);

tests/plugins/reject_some_invoices.py

@@ -18,9 +18,9 @@ def on_payment(payment, plugin):
     if payment['preimage'].endswith('0'):
         # FIXME: Define this!
         WIRE_TEMPORARY_NODE_FAILURE = 0x2002
-        return {'result': {'failure_code': WIRE_TEMPORARY_NODE_FAILURE}}
+        return {'failure_code': WIRE_TEMPORARY_NODE_FAILURE}
 
-    return {'result': {}}
+    return {}
 
 
 plugin.run()