Turn off hardware cursor when screen fade begins.

The compositor was never actually calling the output backend to turn off
the hardware cursor when the screen begins fading.  This would result in
a stuck hardware cursor and movable software cursor for the duration of
the fade/unfade.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>

compositor/compositor.c

@@ -812,8 +812,10 @@ wlsc_output_set_cursor(struct wlsc_output *output,
 
 	prior_was_hardware = wl_list_empty(&device->sprite->link);
 	if (force_sw || output->set_hardware_cursor(output, device) < 0) {
-		if (prior_was_hardware)
+		if (prior_was_hardware) {
 			wlsc_surface_damage(device->sprite);
+			output->set_hardware_cursor(output, NULL);
+		}
 		use_hardware_cursor = 0;
 	} else if (!prior_was_hardware) {
 		wlsc_surface_damage_below(device->sprite);