make ddp logging api to be private (#57999)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57999
make ddp logging api to be private
ghstack-source-id: 128607185
Test Plan: unit test
Reviewed By: rohan-varma
Differential Revision: D28338485
fbshipit-source-id: bd2ae7c78904e93eed88be91876f5a832b5b7886
