mesa/fbobject: propogate Layered when reusing attachments.

When reusing a depth attachment as a stencil, we need to propogate
the layered bit, otherwise we fail to complete the framebuffer.

discovered running ./bin/fbo-depth-array depth-layered-clear
on virgl on haswell.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Cc: "11.1 11.2" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/mesa/main/fbobject.c

@@ -2815,6 +2815,7 @@ reuse_framebuffer_texture_attachment(struct gl_framebuffer *fb,
    dst_att->Complete = src_att->Complete;
    dst_att->TextureLevel = src_att->TextureLevel;
    dst_att->Zoffset = src_att->Zoffset;
+   dst_att->Layered = src_att->Layered;
 }