Remove now-unused variables from tp_traverse and tp_clear methods.

Objects/listobject.c

@@ -2274,7 +2274,6 @@ static int
 list_traverse(PyListObject *o, visitproc visit, void *arg)
 {
 	Py_ssize_t i;
-	PyObject *x;
 
 	for (i = o->ob_size; --i >= 0; )
 		Py_VISIT(o->ob_item[i]);

Objects/typeobject.c

@@ -2213,8 +2213,6 @@ type_traverse(PyTypeObject *type, visitproc visit, void *arg)
 static int
 type_clear(PyTypeObject *type)
 {
-	PyObject *tmp;
-
 	/* Because of type_is_gc(), the collector only calls this
 	   for heaptypes. */
 	assert(type->tp_flags & Py_TPFLAGS_HEAPTYPE);