init: Use /etc/sysctl.d instead of sysctl.conf

Using a monolithic sysctl.conf makes per-device sysctl overrides difficult
to implement. Switch to using --system which will load all conf files
under /etc/sysctl.d.

CQ-DEPEND=CL:313006
BUG=chromium:555785
TEST=create /etc/sysctl.d on device, move /etc/sysctl.conf into
/etc/sysctl.d/00-sysctl.conf.
reboot and verify sysctl -a shows the same settings as the conf file.

Change-Id: I2f529ae210a3fb7d685714aa08ac0c0d2b51a529
Reviewed-on: https://chromium-review.googlesource.com/313153
Commit-Ready: Stephen Barber <smbarber@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed