power: Use --flag=value for arguments to backlight_tool

With the switch to using chromeos::FlagHelper and base::CommandLine,
setting flags using "--flag value" for powerd tools is no longer
supported.

BUG=chromium:421244
TEST=`test_that -b daisy :lab: e:power_.*`

Change-Id: I2cd9e0b6257ddae90431c0a9b78f9794771caa6e
Reviewed-on: https://chromium-review.googlesource.com/222065
Tested-by: Steve Fung <stevefung@chromium.org>
Reviewed-by: Daniel Erat <derat@chromium.org>
Reviewed-by: Ullysses A Eoff <ullysses.a.eoff@intel.com>
Commit-Queue: Ullysses A Eoff <ullysses.a.eoff@intel.com>
(cherry picked from commit 9297d9005cf6e3ffc7a3158cacf67e9856c142fc)
Reviewed-on: https://chromium-review.googlesource.com/240574
Reviewed-by: Yusuf Mohsinally <mohsinally@chromium.org>
Commit-Queue: Bernie Thompson <bhthompson@chromium.org>
Tested-by: Bernie Thompson <bhthompson@chromium.org>
2 files changed