Missing cast with vlc_config_set

(What about some GCCisms for static type checking here... later)

include/vlc_plugin.h

@@ -408,21 +408,21 @@ enum vlc_config_properties
                     (size_t)(sizeof (list) / sizeof (char *)), \
                     (const char *const *)(list), \
                     (const char *const *)(list_text), \
-                    list_update_func);
+                    (vlc_callback_t)(list_update_func));
 
 #define change_integer_list( list, list_text, list_update_func ) \
     vlc_config_set (p_config, VLC_CONFIG_LIST, domain, \
                     (size_t)(sizeof (list) / sizeof (int)), \
                     (const int *)(list), \
                     (const char *const *)(list_text), \
-                    list_update_func);
+                    (vlc_callback_t)(list_update_func));
 
 #define change_float_list( list, list_text, list_update_func ) \
     vlc_config_set (p_config, VLC_CONFIG_LIST, domain, \
                     (size_t)(sizeof (list) / sizeof (float)), \
                     (const float *)(list), \
                     (const char *const *)(list_text), \
-                    list_update_func);
+                    (vlc_callback_t)(list_update_func));
 
 #define change_integer_range( minv, maxv ) \
     vlc_config_set (p_config, VLC_CONFIG_RANGE, (int)(minv), (int)(maxv));