Revert "cgroupfs: need the full path to setup cpuset"

This reverts commit 47f5ede0ec09b393779a7755aa36dc665e2e8fa5.
Revert "cgroupfs: get rid of the redundant error info"

This reverts commit a8117b3361c9caf1397f4dc9bbb5e6de3af3cdff.
Revert "cgroup.c: clean up for handle_cgroup_settings"

This reverts commit 032e28b7675fd03dc19c7af0182ddb93807c2f96.
Revert "bionic: Replace rindex by strrchr"

This reverts commit 86f0eb65a0abc651c656ff602b823ba693f675c5.
Revert "cgroupfs: support older kernels without cgroup.clone_children"

This reverts commit 0a4d93787d4be78dc5e2873cf7c605c01d383792.