drm/i915: Fix assert on pending async-put power domain work when it requeues itself

drm/i915: Fix assert on pending async-put power domain work when it requeues itself

Commit dd839aa857eb ("drm/i915: Fix incorrect assert about pending power domain async-put work")

fixed the assert about a pending work dropping a display power reference
asynchronously, leading to the

drm_WARN_ON(!queue_delayed_work(&power_domains->async_put_work));

warn next time around a power reference was put asynchronously, due to a
stale instance of the work still being pending. However the fix didn't
consider the case where multiple power reference was acquired and put,
requiring the work to requeue itself. Extend the fix for this case as
well canceling the pending instance of the work before it requeues
itself.

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10915
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240530105312.1016485-1-imre.deak@intel.com