Worker: removing unneeded blocked check

  WASSERT(t->execute);

  /* Is there an available worker right now? */

  if ((atomic_load_explicit(&wq->blocked, memory_order_relaxed) == 0) && SEM_TRYWAIT(&wq->available))

  if (SEM_TRYWAIT(&wq->available))

    return task_push_available(t);

  else

    return task_push_block(t);