PERFORCE change 163077 for review

[Hans Petter Selasky]

On Saturday 30 May 2009, Sylvestre Gallon wrote:
> +               ret = libusb20_dev_process(devh->os_priv);
> +               if (ret == 0 || LIBUSB20_ERROR_NO_DEVICE)

ret == LIBUSB20_ERROR_NO_DEVICE

One note:

libusb20 is not thread safe. So you might need an additional lock for that, 
I.E. when you call libusb20_dev_process() and libusb20_tr_submit()++ must be 
atomic. If this cannot be solved in libusb10, I will do something.

--HPS