taskqueue_poll_is_busy
retval = taskqueue_poll_is_busy(tq, &work->work_task);
retval = taskqueue_poll_is_busy(tq, &dwork->work.work_task);
return (taskqueue_poll_is_busy(tq, &work->work_task));
int taskqueue_poll_is_busy(struct taskqueue *queue, struct task *task);