flashrom: Retain support for /run/lock/flashrom_powerd.lock.

Make flashrom fall back to creating a lock file at
/run/lock/flashrom_powerd.lock if /run/lock/power_override
doesn't exist. This is needed to support the case during
system updates where a recent version of flashrom is running
on an old system image.

BUG=chromium:784651
BRANCH=None
TEST=manual: "flashrom -w" creates a file in
     /run/lock/power_override if it exists or at
     /run/lock/flashrom_powerd.lock otherwise

Change-Id: Ia3bba0a01f40f5245c4b667de1ca638febe48acc
Signed-off-by: Daniel Erat <derat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/902169
Commit-Ready: Dan Erat <derat@chromium.org>
Tested-by: Dan Erat <derat@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
1 file changed