Fix Padded Batch Error 12282
Author: will-rice
Pull request: yes

This fixes the padded batch [issue](https://github.com/huggingface/transformers/issues/12282). The error was generated due to the maximum sequence length of the attention mask not matching the padded sequence length of the hidden_states. `np.allclose` now passes with a 1e-2 absolute tolerance.

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Fixes # (issue)


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Comments:
The `1e-2` absolute tolerance still bothers me, but I'm not 100% sure where the variation is coming from. One thing I thought about was if the padding could have a subtle effect when passed through the `feature_extractor`.