Fix identifier shadowing in tracer (#16480)
Summary:
This was causing build failures under `-Werror` targets under optimized build modes
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16480
Differential Revision: D13857621
Pulled By: jamesr66a
fbshipit-source-id: 2990b987dbca943298ad478c9ee2792236f5fa5b
