Fix compilation bug with CUDA 12.1

[Edenzzzz]

Description

Please include a brief summary of the changes, relevant motivation and context.

Fixes # (issue)

Type of change

• [ ] Documentation change (change only to the documentation, either a fix or a new content)
• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Infra/Build change
• [ ] Code refractor

Changes

This has been mentioned in #560 but somehow someone just changed it back... Importing , which imports , after defining nv_bfloat16 triggers re-declaration error.

Checklist:

• [x] I have read and followed the contributing guidelines
• [x] The functionality is complete
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[timmoon10]

/te-ci pytorch

[Edenzzzz]

Thanks for catching this bug again. We missed the change in #757.

Please sign the commit (instructions) and I this is ready to go.

Sounds good!