This PS adds a warning if the hugetlb cgroup controller is enabled
as it prevents restarts of the libvirt pod without shutting down
kvm vms. The controller can be disabled by passing
`cgroup_disable=hugetlb` to the kernel params.
Change-Id: Idd26fd3c19191f3c3e0aeb6fa3efa9a4ec48ee54
Signed-off-by: Pete Birley <pete@port.direct>