vl: Do some subpicture validation.
diff --git a/src/gallium/state_trackers/xorg/xvmc/xvmc_private.h b/src/gallium/state_trackers/xorg/xvmc/xvmc_private.h
index 82f6fca..1e2dfb4 100644
--- a/src/gallium/state_trackers/xorg/xvmc/xvmc_private.h
+++ b/src/gallium/state_trackers/xorg/xvmc/xvmc_private.h
@@ -43,6 +43,8 @@
 {
    struct vl_context *vctx;
    struct pipe_surface *backbuffer;
+   unsigned short subpicture_max_width;
+   unsigned short subpicture_max_height;
 } XvMCContextPrivate;
 
 typedef struct