vdpau: eliminate dead code

modules/hw/vdpau/chroma.c

@@ -472,7 +472,6 @@ static picture_t *MixerRender(filter_t *filter, picture_t *src)
     }
 
     src = sys->import(filter, src);
-
     /* Update history and take "present" picture field */
     if (likely(src != NULL))
     {

modules/hw/vdpau/picture.c

@@ -110,14 +110,3 @@ vlc_vdp_video_field_t *vlc_vdp_video_copy(vlc_vdp_video_field_t *fold)
     atomic_fetch_add(&frame->refs, 1);
     return fnew;
 }
-
-vlc_vdp_video_field_t *vlc_vdp_video_detach(picture_t *pic)
-{
-    vlc_vdp_video_field_t *field = pic->context;
-
-    assert(pic->format.i_chroma == VLC_CODEC_VDPAU_VIDEO_420
-        || pic->format.i_chroma == VLC_CODEC_VDPAU_VIDEO_422);
-    //assert(!picture_IsReferenced(pic));
-    pic->context = NULL;
-    return field;
-}

modules/hw/vdpau/vlc_vdpau.h

@@ -275,10 +275,4 @@ VdpStatus vlc_vdp_video_attach(vdp_t *, VdpVideoSurface, picture_t *);
  * (the underlying VDPAU video surface is shared).
  */
 vlc_vdp_video_field_t *vlc_vdp_video_copy(vlc_vdp_video_field_t *);
-
-/**
- * Detaches a VDPAU video surface as context from a VLC picture.
- * @return the detached context, or NULL on error.
- */
-vlc_vdp_video_field_t *vlc_vdp_video_detach(picture_t *);
 #endif