shorten output format (#1073)
Summary:
Currently, the output results are too long when three or more backends run together. So we can shorten this output format.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1073
Reviewed By: FindHao
Differential Revision: D38463053
Pulled By: xuzhao9
fbshipit-source-id: 7dc087fd016c086991d78d350f356ef5105e4dd9
