SF bug [#467265] Compile errors on SuSe Linux on IBM/s390.

Unknown whether this fixes it.
- stringobject.c, PyString_FromFormatV:  don't assume that va_list is of
  a type that can be copied via an initializer.
- errors.c, PyErr_Format:  add a va_end() to balance the va_start().

Python/errors.c

@@ -407,7 +407,7 @@ PyErr_Format(PyObject *exception, const char *format, ...)
 	string = PyString_FromFormatV(format, vargs);
 	PyErr_SetObject(exception, string);
 	Py_XDECREF(string);
-	
+	va_end(vargs);
 	return NULL;
 }