kernel/workqueue: Bind rescuer to unbound cpumask for WQ_UNBOUND
At the time they are created unbound workqueues rescuers currently use
cpu_possible_mask as their affinity, but this can be too wide in case a
workqueue unbound mask has been set as a subset of cpu_possible_mask.
Make new rescuers use their associated workqueue unbound cpumask from
the start.
Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>