bpo-30592: Fixed error messages for some builtins. (#1996)

Error messages when pass keyword arguments to some builtins that
don't support keyword arguments contained double parenthesis: "()()".
The regression was introduced by bpo-30534.
diff --git a/Objects/weakrefobject.c b/Objects/weakrefobject.c
index da05950..f600179 100644
--- a/Objects/weakrefobject.c
+++ b/Objects/weakrefobject.c
@@ -332,7 +332,7 @@
 {
     PyObject *tmp;
 
-    if (!_PyArg_NoKeywords("ref()", kwargs))
+    if (!_PyArg_NoKeywords("ref", kwargs))
         return -1;
 
     if (parse_weakref_init_args("__init__", args, kwargs, &tmp, &tmp))