FROMGIT: cgroup/cpuset: Iterate only if DEADLINE tasks are present

update_tasks_root_domain currently iterates over all tasks even if no
DEADLINE task is present on the cpuset/root domain for which bandwidth
accounting is being rebuilt. This has been reported to introduce 10+ ms
delays on suspend-resume operations.

Skip the costly iteration for cpusets that don't contain DEADLINE tasks.

Bug: 238390134
Reported-by: Qais Yousef <qyousef@layalina.io>
Link: https://lore.kernel.org/lkml/20230206221428.2125324-1-qyousef@layalina.io/


Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
(cherry picked from commit c0f78fd5
https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git

 cgroup/for-6.5)
Signed-off-by: Qais Yousef <qyousef@google.com>
Change-Id: Idc3f348d90b1024be2408fe8a855e09c354409c8