Git reset fix for bot update
Git reset fix for bot update

This fixes the failure condition where if there is a bad checkout, the following reset command would
fail with 128.

BUG=339168

Review URL: https://codereview.chromium.org/159983006

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@250552 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build