Remove onnx export expects (#21238)
Summary:
We're not getting much from checking the export strings, and they are noisy and slow development. DIdn't realize they existed until now.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21238
Differential Revision: D15604256
Pulled By: eellison
fbshipit-source-id: 488e9401231228cffe132dab99d519563fa63afc
