faft: Revert the code which is accidentally removed on UpdateECBin test

When we refactored the firmware backup and restore methods, we accidentally
removed the code and caused error. This CL is to revert the code.

Previous CL: https://gerrit.chromium.org/gerrit/32528

BUG=chromium-os:33641
TEST=None, trivial code revert.

Change-Id: Ieffb9c5d2b780ac4f5852b1e26d58edc2ad2bfbd
Reviewed-on: https://gerrit.chromium.org/gerrit/37611
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>
1 file changed