[Examples] Replace `print` statement with `logger.info` in QA example utils
# What does this PR do?
Earlier in `utils_qa.py`,  `run_qa_beam_search.py` was using `print()` for showing states saving file paths, while `run_qa.py` using `logger.info()` which seems more appropriate.

This PR replace `print()` with `logger.info()`. 

## Before submitting
- [ ] 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?
- [x] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link to it if that's the case. Discussed in [Issue](https://github.com/huggingface/transformers/issues/12363)
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/master/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/master/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?
@stas00 @sgugger 
Thanks!