fix typo

Cython/Utility/CythonFunction.c

@@ -361,7 +361,7 @@ __Pyx_CyFunction_get_signature(__pyx_CyFunctionObject *op) {
     if (unlikely(!signature_class))
         goto bad;
     // return Signature.from_function(op)
-    signature = PyObject_CallMethodObjectArgs(signature_class, PYIDENT("from_function"), op, NULL);
+    signature = PyObject_CallMethodObjArgs(signature_class, PYIDENT("from_function"), op, NULL);
     Py_DECREF(signature_class);
     if (likely(signature))
         return signature;