Run example_outputs under no_grad (#1558)
Summary:
I think example_outputs is keeping a lot of memory alive for longer than is needed.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1558
Reviewed By: davidberard98
Differential Revision: D45137409
Pulled By: xuzhao9
fbshipit-source-id: a657b19d84d3f6f03a9ace604995c968e0140444
