Fix return values of _setMenuCells

Author: renonick87

lib/js/src/manager/screen/menu/_MenuManagerBase.js

@@ -142,17 +142,16 @@ class _MenuManagerBase extends _SubManagerBase {
     /**
      * Creates and sends all associated Menu RPCs
      * @param {MenuCell[]} cells - The menu cells that are to be sent to the head unit, including their sub-cells.
-     * @returns {Promise} - A Promise that resolves to whether the operation was successful
      */
     _setMenuCells (cells = []) {
         if (cells === null) {
             console.error('MenuManagerBase - Cells list is null. Skipping...');
-            return Promise.resolve(true);
+            return;
         }
 
         if (!this._menuCellsAreUnique(cells, [])) {
             console.error('MenuManagerBase - Not all set menu cells are unique, but that is required');
-            return Promise.resolve(false);
+            return;
         }
 
         // Create a deep copy of the list so future changes by developers don't affect the algorithm logic