Add an enterSubmenu routine to centralize that behavior

menu.cpp

@@ -30,3 +30,14 @@ void runActiveMenu(const ButtonPress_e tuner_button,
     }
   }//end switch
 }
+
+void enterSubmenu(Menu_t *const submenu)
+{
+  Menu_t* current_menu = rootMenu;
+  while(nullptr != current_menu->active_submenu){
+    current_menu = current_menu->active_submenu;
+  }
+  current_menu->active_submenu = submenu;
+  submenu->initMenu();
+}
+

menu.h

@@ -30,3 +30,5 @@ void runActiveMenu(const ButtonPress_e tuner_button,
                    const ButtonPress_e touch_button,
                    const Point touch_point,
                    const int16_t knob);
+
+void enterSubmenu(Menu_t *const submenu);

menu_main_buttons.cpp

@@ -588,6 +588,5 @@ void osMenu(){
 }
 
 void osNumpad(){
-  numpadMenu->initMenu();
-  rootMenu->active_submenu = numpadMenu;
+  enterSubmenu(numpadMenu);
 }