usbdi.c change

Can you make the following change to usbdi.c lines 970 – 981. It fixes a problem with restarting a transfer from a callback.

#if 1
        /* 
         * COLIN_CALLBACK_FIX
         * modification extracted from FREEBSD74 sources
         */

        /*
         * For repeat operations, call the callback first, as the xfer
         * will not go away and the "done" method may modify it. Otherwise
         * reverse the order in case the callback wants to free or reuse
         * the xfer.
         */
        if (repeat) {
                if (xfer->callback)
                        xfer->callback(xfer, xfer->priv, xfer->status);
                pipe->methods->done(xfer);
        } else {
                pipe->methods->done(xfer);
                if (xfer->callback)
                        xfer->callback(xfer, xfer->priv, xfer->status);
        }
#else

        if (xfer->callback)
                xfer->callback(xfer, xfer->priv, xfer->status);

#ifdef DIAGNOSTIC
        if (pipe->methods->done != NULL)
                pipe->methods->done(xfer);
        else
                printf("usb_transfer_complete: pipe->methods->done == NULL\n");
#else
        pipe->methods->done(xfer);
#endif

#endif