[Wav2Vec2] Fix documentation inaccuracy
Author: MikeG112
Pull request: yes

# What does this PR do?
This PR resolves two Wav2Vec2 documentation statements that I believe are typos.
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Fixes # (issue)


## Before submitting
- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/master/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
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      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/master/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


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Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
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Based on revision history, I assume @patrickvonplaten is an appropriate reviewer.

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Comments:
Great! Thanks a lot for correcting those :-)


Hey @MikeG112, sorry could you run `make style` once to fix the code quality issue? Then we can merge :-)

Hey @patrickvonplaten, absolutely, I added the changes made by `make style`. Thanks for the review and the wav2vec2 implementation :)