Remove an XXX that is unnecessary.

Python/ceval.c

@@ -490,7 +490,6 @@ volatile int _Py_Ticker = 100;
 PyObject *
 PyEval_EvalCode(PyCodeObject *co, PyObject *globals, PyObject *locals)
 {
-	/* XXX raise SystemError if globals is NULL */
 	return PyEval_EvalCodeEx(co,
 			  globals, locals,
 			  (PyObject **)NULL, 0,