Still occurs -12 Not supported for USB camera.

For both of libusb and libusbx, it occurs same problem of return -12 at uvc_open() after success of uvc_find_device().

Tested with Windows10Pro 64bit, MinGW-W64 7.1.2 (64bit) and libusbx.

Log:
```
UVC initialized
Device found
uvc_open: Not supported (-12)
UVC exited
```