When rietveld.py overrides upload.py's logging module, it generally works fine...
until someone tries to run upload.py with any level of verbosity. Then the
calls to logging.getLogger and logging.INFO/logging.DEBUG fail. This patches
upload.py to properly use a module-scope logger so that rietveld.py doesn't
have to perform invasive surgery, and everything just works.

This version of upload.py taken from upstream Rietveld at:
changeset:   1267:d7b39eca7dbe
branch:      chromium

R=djacques@chromium.org, maruel@chromium.org

Review URL: https://codereview.chromium.org/221423007

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@262793 0039d316-1c4b-4281-b951-d872f2087c98