fix bug when ep_degree == sharding_degree (#74268)

Author: FeixLiu

python/paddle/distributed/fleet/utils/tensor_fusion_helper.py

@@ -807,6 +807,7 @@ def _comm_grads(self):
     def scale_grads(self):
         if self.need_reduce_scale_sync():
             if self._comm_group.nranks == 1 and self._task is None:
+                self._reset_params_checked_in()
                 return
             assert self._task is not None, "Task is not initialized."
             self._task.wait()