Revert "memcg: Allow non-root users permission to control memory"

This reverts commit 93d46ff4 ("memcg: Allow
non-root users permission to control memory"), as the
required function hook is already available.

Change-Id: Ia6c7da33e16a1c98534267fbce91ba3da2213ba4
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>