CrOS: Fix chromiumos builder directory names.
CrOS: Fix chromiumos builder directory names.

BUG=chromium:468178
TEST=local
  - Confirmed named on local master.

Review URL: https://codereview.chromium.org/1489383003 .

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@297807 0039d316-1c4b-4281-b951-d872f2087c98

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