Add required backslash for macro expansion

Marlin/ultralcd.cpp

@@ -1035,7 +1035,7 @@ void lcd_sdcard_menu() {
         *((_type*)editValue) = ((_type)((int32_t)encoderPosition + minEditValue)) / scale; \
         lcd_goto_menu(prevMenu, prevEncoderPosition); \
       } \
-    return isClicked;
+      return isClicked; \
     } \
     void menu_edit_callback_ ## _name () { \
       if (menu_edit_ ## _name ()) (*callbackFunc)(); \