fix loss normalization for ddp training

haoneng.lhn

2023-12-07 4152cf4615e234b9892703a8e088cdd51937fc13

 funasr/build_utils/build_optimizer.py

@@ -23,4 +23,6 @@
    if optim_class is None:
        raise ValueError(f"must be one of {list(optim_classes)}: {args.optim}")
    optimizer = optim_class(model.parameters(), **args.optim_conf)
    return optimizer

    optimizers = [optimizer]
    return optimizers