Fixed memory leak in error branch of object_repr which may leak a reference to mod when type_name returns NULL. CID 715371

Objects/typeobject.c

@@ -2925,8 +2925,10 @@ object_repr(PyObject *self)
         mod = NULL;
     }
     name = type_name(type, NULL);
-    if (name == NULL)
+    if (name == NULL) {
+        Py_XDECREF(mod);
         return NULL;
+    }
     if (mod != NULL && PyUnicode_CompareWithASCIIString(mod, "builtins"))
         rtn = PyUnicode_FromFormat("<%U.%U object at %p>", mod, name, self);
     else