Remove unnecessary fetch and reset on builder checkout. (#23792)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23792
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Differential Revision: D16648539
Pulled By: ezyang
fbshipit-source-id: f713fca6d428c03ed31aad18464c92265fb81420
