remove some code part never been called (#35033)
Summary:
At title. Found that `THBlas_(swap)` was never be used. So I remove it from repo. Please help review patch, and any suggestions are welcomed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35033
Differential Revision: D20918998
Pulled By: albanD
fbshipit-source-id: 93af8429231421185db0ccdfdd44e349a8f68c67
