fix loss normalization for ddp training

haoneng.lhn

2023-12-07 4152cf4615e234b9892703a8e088cdd51937fc13

 funasr/layers/inversible_interface.py

@@ -11,4 +11,4 @@
        self, input: torch.Tensor, input_lengths: torch.Tensor = None
    ) -> Tuple[torch.Tensor, torch.Tensor]:
        # return output, output_lengths
        raise NotImplementedError
        raise NotImplementedError