vrend: Don't set resolve filter for non-RGBA buffers

When we blit between depth or stencil buffers, but MSAA is enabled,
we can hit that path and set the GL_SCALED_RESOLVE_NICEST_EXT. This
causes the blit to fail. Fix this by not going in that path for
depth/stencil buffers.

Fixes:
dEQP-GLES3.functional.fbo.invalidate.whole.unbind_blit_msaa_color
dEQP-GLES3.functional.fbo.invalidate.whole.unbind_blit_msaa_depth
dEQP-GLES3.functional.fbo.invalidate.whole.unbind_blit_msaa_stencil
dEQP-GLES3.functional.fbo.invalidate.sub.unbind_blit_msaa_color
dEQP-GLES3.functional.fbo.invalidate.sub.unbind_blit_msaa_depth
dEQP-GLES3.functional.fbo.invalidate.sub.unbind_blit_msaa_stencil

Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>

src/vrend_renderer.c

@@ -5916,7 +5916,8 @@ static void vrend_renderer_blit_int(struct vrend_context *ctx,
       use_gl = true;
 
    /* for scaled MS blits we either need extensions or hand roll */
-   if (src_res->base.nr_samples > 1 &&
+   if (info->mask & PIPE_MASK_RGBA &&
+       src_res->base.nr_samples > 1 &&
        src_res->base.nr_samples != dst_res->base.nr_samples &&
        (info->src.box.width != info->dst.box.width ||
         info->src.box.height != info->dst.box.height)) {