replace env.seed by end.reset(seed=seed) #1271 (#1272)
Summary: Pull Request resolved: https://github.com/pytorch/benchmark/pull/1272
Reviewed By: davidberard98
Differential Revision: D40872958
Pulled By: xuzhao9
fbshipit-source-id: cdcd3dbbfe75385eca2aa8fba7aa783a43cd48a7
