If 3D is enabled, but userspace requests a dumb buffer, we will
call CTX_ATTACH_RESOURCE before actually creating the context.

Fixes: 72b48ae8 ("drm/virtio: enqueue virtio_gpu_create_context after the first 3D ioctl")
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200501185557.740-1-gurchetansingh@chromium.orgSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>