mesa/texgetimage: fix missing stencil check
GetTexImage can read to stencil8 but only from a stencil or depthstencil textures. This fixes a bunch of failures in CTS GL33-CTS.gtf32.GL3Tests.packed_pixels Reviewed-by:Marek Olšák <marek.olsak@amd.com> Cc: "11.0" <mesa-stable@lists.freedesktop.org> Signed-off-by:
Dave Airlie <airlied@redhat.com>