Instead just do a git checkout --force, since there are some states that reset cannot fix.

BUG=606420

Review URL: https://codereview.chromium.org/1916973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@300176 0039d316-1c4b-4281-b951-d872f2087c98