Remove jit from the framework code (#1787)
Summary:
Jit(torchscript) is now in archive mode and there is no need that we add it to the explicit options.
Jit(torchscript) is still supported with the extra args option `--backend torchsript`.
Fixes https://github.com/pytorch/benchmark/issues/1777
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1787
Reviewed By: msaroufim
Differential Revision: D47774649
Pulled By: xuzhao9
fbshipit-source-id: 7eb25e54d016da9a49b93c514cc302f6d8d4573c
