Fix FTBFS caused by incompatible cast

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

xine_artsplugin/audio_fifo_out.c

@@ -354,7 +354,7 @@ static ao_driver_t * _arts_open(audio_driver_class_t *driver_class, const void *
 	return &_ao_driver->ao_driver;
 }
 
-static void *_arts_plugin_class_init(xine_t *xine, void *data) {
+static void *_arts_plugin_class_init(xine_t *xine, const void *data) {
 	fifo_class_t *cl;
 	
 	cl = (fifo_class_t *) malloc(sizeof(fifo_class_t));
@@ -376,7 +376,7 @@ static ao_info_t _arts_info =
 
 plugin_info_t arts_xine_plugin_info[] =
 {
-     { PLUGIN_AUDIO_OUT, AUDIO_OUT_IFACE_VERSION, "arts", XINE_VERSION_CODE, &_arts_info, _arts_plugin_class_init },
+     { PLUGIN_AUDIO_OUT, AUDIO_OUT_IFACE_VERSION, "arts", XINE_VERSION_CODE, &_arts_info, &_arts_plugin_class_init },
      { PLUGIN_NONE, 0, "", 0, NULL, NULL }
 };
 #endif