Not flatten states when use_orig_param is True and sharding is NO_SHARD (#100189)
When use_orig_param is True and sharding is NO_SHARD, parameters and states are not flattened, so optimizer states should not be flattened as well. The unit test will fail without the fix.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100189
Approved by: https://github.com/awgu
