The Vhost-user specification changed feature and request naming from _SLAVE_ to _BACKEND_. This patch adopts the new naming convention. Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> Message-Id: <20230208203259.381326-3-maxime.coquelin@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>