cros_bundle_firmware: Use enter/exit instead of del
This change makes use of Python's 'with' construct which is a nicer way to
deal with the finalization problem.
BUG=chromium-os:17298
TEST=run cros_bundle_firmware; check that output is still consistent and
output directory is removed.
Change-Id: I81045a5e52af68f512dbf4a48a6151832e7c47d5
Reviewed-on: http://gerrit.chromium.org/gerrit/5592
Reviewed-by: Che-Liang Chiou <clchiou@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
3 files changed
