Revert "ANDROID: sched/fair: prevent possible infinite loop in sched_group_energy"

This reverts commit 727eafb4.

This is a preparation change for merging android-4.14 commit
e709f59a into msm-4.14 branch.
The reverted change is committed already as:

536e7d5d sched/fair: prevent possible infinite loop in compute_energy()

Change-Id: I1f44e4b332b973f71d8e5945b7557b8c2e98030f
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>