[FSDP] named_buffers fix (#74517)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74517
Partially addresses https://github.com/pytorch/pytorch/issues/73890 to fix named_buffers by stripping FSDP info in summon_full_params context, similar to named_params.
ghstack-source-id: 152309646
(Note: this ignores all push blocking failures!)
Test Plan: CI
Reviewed By: zhaojuanmao
Differential Revision: D35023191
fbshipit-source-id: 091c7afa73c595f54e303dbfc938010e08278d64
(cherry picked from commit 8d1dd2e99b00e493d167343de006614165aa77f9)
