Revert unneed code change.

We can just always call _PyType_CheckConsistency() since it handles
types that are not yet ready.

Author: nascheme

Objects/typeobject.c

@@ -9497,9 +9497,7 @@ type_ready(PyTypeObject *type, int initial, int add_subclasses)
 
     stop_readying(type);
 
-    if (add_subclasses) {
-        assert(_PyType_CheckConsistency(type));
-    }
+    assert(_PyType_CheckConsistency(type));
     return 0;
 
 error: