Change firmware update option in release only mode

In release only mode, we need to run firmware update in --mode=recovery
instead of --nide=factory_install.

BUG=chrome-os-partner:20735
TEST=Script Run Succeed

Change-Id: I026e3ac6c0f65c4adb2cf23b360d42b4b84670ce
Reviewed-on: https://gerrit.chromium.org/gerrit/65553
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Chun-Yen Ho <chho@chromium.org>
Tested-by: Chun-Yen Ho <chho@chromium.org>
1 file changed