Fix upload_to_google_storage.py.
Fix upload_to_google_storage.py.

r293250 broke it. I didn't realize that check_bucket_permissions
was shared code. It now only returns a single value.

TBR=vadimsh@chromium.org

Review URL: https://codereview.chromium.org/782643002

git-svn-id: bd64dd6fa6f3f0ed0c0666d1018379882b742947@293256 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

svn2github/chromium-depot-tools,svn2github/chromium-depot-tools,svn2github/chromium-depot-tools