choikiwon

I think this commit([b4fcd98](https://github.com/microsoft/DeepSpeed/commit/b4fcd98ff096cd367dcfeb3c1d28a15d34447c66)) occurs the issue. previous commit([32d979](https://github.com/microsoft/DeepSpeed/commit/32d97976ce08f00228ceb55a2d93005bd8b2769a)) works fine.