cgroup/cpuset: Check partition conflict with housekeeping setup

cgroup/cpuset: Check partition conflict with housekeeping setup

A user can pre-configure certain CPUs in an isolated state at boot time
with the "isolcpus" kernel boot command line option. Those CPUs will
not be in the housekeeping_cpumask(HK_TYPE_DOMAIN) and so will not
be in any sched domains. This may conflict with the partition setup
at runtime. Those boot time isolated CPUs should only be used in an
isolated partition.

This patch adds the necessary check and disallows partition setup if the
check fails.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>