dec/hevc: Use the same equation for each metadata buffer no matter slice type
dec/hevc: Use the same equation for each metadata buffer no matter slice type

Signed-off-by: Xiang, Haihao <8d677183e5993577d4fa73a419b76987913292d6@intel.com>
Reviewed-by: Zhao Yakui <21bae65ecea50a19bd9d0fef489914760189fd5b@intel.com>

gbeauchesne/libva-intel-driver,gbeauchesne/libva-intel-driver,gbeauchesne/libva-intel-driver,gbeauchesne/libva-intel-driver,gbeauchesne/libva-intel-driver