Use manual file writing, it's just two lines.

TBR=nsylvain@chromium.org
BUG=
TEST=git try works with non-ascii patches


Review URL: https://chromiumcodereview.appspot.com/10815009

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@147447 0039d316-1c4b-4281-b951-d872f2087c98