fix issue with file progress bar going over 100%

fixes CNVS-16869

You have some cases where a user has uploaded more than their quota
limit in which case, the progress bar was overflowing and creating some
style issues.

Setting up a user with more space used than in their quota
1. Create a user
2. Upload 50MB of files
3. In the console, change the users quota limit to 25MB (user.storage_quota = 25.megabytes)
4. Save the user
5. Reload the browser page.

Test Plan
Given you have new files enabled
And you have used over 100% of your quota space
When you go to your users files section
Then the file quota used bar should be 100%

Change-Id: If39aa3106cd7eea2f7d4586623f2f35069db9062
Reviewed-on: https://gerrit.instructure.com/44588
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cosme Salazar <cosme@instructure.com>
Reviewed-by: Dan Minkevitch <dan@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>