Revert "cgroup: Add generic cgroup subsystem permission checks"

This reverts commit 53b5e2f0.

Part of Chromium commit series:

CHROMIUM: remove Android's cgroup generic permissions checks

The implementation is utterly broken, resulting in all processes being
allows to move tasks between sets (as long as they have access to the
"tasks" attribute), and upstream is heading towards checking only
capability anyway, so let's get rid of this code.

BUG=b:31790445,chromium:647994
TEST=Boot android container, examine logcat

Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/394967


Reviewed-by: Ricky Zhou <rickyz@chromium.org>
Reviewed-by: John Stultz <john.stultz@linaro.org>

Change-Id: I96145659b2681a327b715d60127f994eabd9eeaa
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>