Add test to the set_module() interface (#1959)
Summary:
All models should have a workable `set_module()` interface to work with the backends.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1959
Reviewed By: aaronenyeshi
Differential Revision: D49914823
Pulled By: xuzhao9
fbshipit-source-id: 7e03db0a850e19337e5a61eaeaf4090bc526c01b
