Fix case light menu toggle

Marlin/ultralcd.cpp

     // Switch case light on/off
     //
     #if ENABLED(MENU_ITEM_CASE_LIGHT)
-      MENU_ITEM_EDIT_CALLBACK(bool, MSG_CASE_LIGHT, case_light_on, update_case_light);
+      MENU_ITEM_EDIT_CALLBACK(bool, MSG_CASE_LIGHT, &case_light_on, update_case_light);
     #endif
 
     if (planner.movesplanned() || IS_SD_PRINTING) {