faft: Reload the firmware image after we modify it

Because we cache the firmware image in the FAFTClient class, we should reload
it after any modification. Otherwise, it causes issues, like multiple GBB flags
clearing.

BUG=chromium-os:32973
TEST=flash the firmware image from buildbot and
     run firmware_RollbackFirmware/control.dev passed.

Change-Id: Ida1f150093296ca9dac8e895c076d6a1a9b53113
Reviewed-on: https://gerrit.chromium.org/gerrit/28476
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Ready: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
2 files changed