[media] uvcvideo: Fix a wrong macro

Don't mix up UVC_BUF_STATE_* and VB2_BUF_STATE_* codes.

Fixes: 6998b6fb ("[media] uvcvideo: Use videobuf2-vmalloc")

Cc: stable@vger.kernel.org
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>