This reverts commit f40fd36c.

According to the documentation below, `--region` is the current flag. If you're
using an older version of the tools that use `--location`, you can customize the
commands in your Packer config with `bundle_vol_command` and `bundle_upload_command`

- http://docs.aws.amazon.com/AWSEC2/latest/CommandLineReference/CLTRG-ami-upload-bundle.html
- https://www.packer.io/docs/builders/amazon-instance.html