CHERRYPICK: Suprresing grep output in battery cut-off scripts.

BUG=chrome-os-partner:25935
TEST=Factory wipe and check the battery is cut-off.
     Factory reset and check the battery is cut-off

Original Change-Id: I7ea3a903bc58ce35419c65da3821e9a8070b9872
Original Reviewed-on: https://chromium-review.googlesource.com/187770
Original Commit-Queue: Bowgo Tsai <bowgotsai@chromium.org>
Original Tested-by: Bowgo Tsai <bowgotsai@chromium.org>
Original Reviewed-by: Bowgo Tsai <bowgotsai@chromium.org>

Change-Id: Icc9c785f71194f5fcbb77cddf0f986bdc802fb41
Reviewed-on: https://chromium-review.googlesource.com/187794
Commit-Queue: JAMES C Chen <james.c.chen@intel.com>
Tested-by: JAMES C Chen <james.c.chen@intel.com>
Reviewed-by: Bowgo Tsai <bowgotsai@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/189638
3 files changed