Cleanup 'k' when the creation of PySTEntryObject fails. ad3824a90261 used to…

Cleanup 'k' when the creation of PySTEntryObject fails. ad3824a90261 used to decref 'k' in too many error cases.

Python/symtable.c

@@ -28,8 +28,10 @@ ste_new(struct symtable *st, identifier name, _Py_block_ty block,
     if (k == NULL)
         goto fail;
     ste = PyObject_New(PySTEntryObject, &PySTEntry_Type);
-    if (ste == NULL)
+    if (ste == NULL) {
+        Py_DECREF(k);
         goto fail;
+    }
     ste->ste_table = st;
     ste->ste_id = k; /* ste owns reference to k */