vebox: fix denoising when IECP is enabled.
vebox: fix denoising when IECP is enabled.

If IECP is enabled, for instance when color conversion is performed
or ProcAmp adjustments are applied, the ultimate denoised output with
additional processing operations applied is the Current Output frame,
not the plain Current Denoised Output frame.

Signed-off-by: Gwenole Beauchesne <729713629d9640cc095f1c77c692e1881f8093c4@intel.com>

01org/iotg-lin-gfx-va-driver,01org/iotg-lin-gfx-va-driver,uartie/vaapi-intel-driver,chenxianqin/vaapi-intel-driver,gbeauchesne/libva-intel-driver,uartie/vaapi-intel-driver,gbeauchesne/libva-intel-driver,chenxianqin/vaapi-intel-driver,gbeauchesne/libva-intel-driver,uartie/vaapi-intel-driver,gbeauchesne/libva-intel-driver,gbeauchesne/libva-intel-driver,chenxianqin/vaapi-intel-driver,uartie/vaapi-intel-driver,01org/iotg-lin-gfx-va-driver,uartie/vaapi-intel-driver,01org/iotg-lin-gfx-va-driver,chenxianqin/vaapi-intel-driver,chenxianqin/vaapi-intel-driver,01org/iotg-lin-gfx-va-driver