The drm_prime_pages_to_sg() function never returns NULL pointers, only
error pointers and valid pointers.
Signed-off-by: NHaixia Shi <hshi@chromium.org>
Reviewed-by: NStéphane Marchesin <marcheu@chromium.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>