usb_task_pending
KASSERT(!usb_task_pending(xfer->ux_pipe->up_dev, &xfer->ux_aborttask));
KASSERT(!usb_task_pending(xfer->ux_pipe->up_dev, &xfer->ux_aborttask));
KASSERT(!usb_task_pending(xfer->ux_pipe->up_dev, &xfer->ux_aborttask));
bool usb_task_pending(struct usbd_device *, struct usb_task *);
KASSERT(!usb_task_pending(un->un_udev, &unp->unp_ticktask));