Clarify type of source_surface as VDP_INVALID_HANDLE
Clarify type of source_surface as VDP_INVALID_HANDLE

(version 2, supercedes "Clarify type of source_surface")

VDPAU takes special action if source_surface is VDP_INVALID_HANDLE,
not if it is NULL, in both VdpOutputSurfaceRenderOutputSurface
and VdpOutputSurfaceRenderBitmapSurface.

Reviewed-by: Christian König <c7ea837d7a46effe4232b086213468b8b31643bf@amd.com>
Signed-off-by: Aaron Plattner <7c39395e2e801146cdbd7fb4a41282e4f38db44e@nvidia.com>

Distrotech/libvdpau,mosterta/libvdpau,mosterta/libvdpau,mosterta/libvdpau,Distrotech/libvdpau,Distrotech/libvdpau