Reorder code and decls so it's compilable with gcc 2.96 (C89).

Modules/timemodule.c

@@ -354,9 +354,10 @@ static int
 gettmarg(PyObject *args, struct tm *p)
 {
 	int y;
-	memset((void *) p, '\0', sizeof(struct tm));
 	PyObject *t = NULL;
 
+	memset((void *) p, '\0', sizeof(struct tm));
+
 	if (PyTuple_Check(args)) {
 		t = args;
 		Py_INCREF(t);