Move single-use to lambdas

Marlin/src/lcd/menu/menu_main.cpp

 #define MACHINE_CAN_STOP (EITHER(SDSUPPORT, HOST_PROMPT_SUPPORT) || defined(ACTION_ON_CANCEL))
 #define MACHINE_CAN_PAUSE (ANY(SDSUPPORT, HOST_PROMPT_SUPPORT, PARK_HEAD_ON_PAUSE) || defined(ACTION_ON_PAUSE))
 
-#if MACHINE_CAN_STOP
-  void menu_abort_confirm() {
-    MenuItem_confirm::select_screen(
-      GET_TEXT(MSG_BUTTON_STOP), GET_TEXT(MSG_BACK),
-      ui.abort_print, ui.goto_previous_screen,
-      GET_TEXT(MSG_STOP_PRINT), (PGM_P)nullptr, PSTR("?")
-    );
-  }
-#endif // MACHINE_CAN_STOP
-
 #if ENABLED(PRUSA_MMU2)
   #include "../../lcd/menu/menu_mmu2.h"
 #endif
       ACTION_ITEM(MSG_PAUSE_PRINT, ui.pause_print);
     #endif
     #if MACHINE_CAN_STOP
-      SUBMENU(MSG_STOP_PRINT, menu_abort_confirm);
+      SUBMENU(MSG_STOP_PRINT, []{
+        MenuItem_confirm::select_screen(
+          GET_TEXT(MSG_BUTTON_STOP), GET_TEXT(MSG_BACK),
+          ui.abort_print, ui.goto_previous_screen,
+          GET_TEXT(MSG_STOP_PRINT), (PGM_P)nullptr, PSTR("?")
+        );
+      });
     #endif
     SUBMENU(MSG_TUNE, menu_tune);
   }

Marlin/src/lcd/menu/menu_media.cpp

   ui.reset_status();
 }
 
-#if ENABLED(SD_MENU_CONFIRM_START)
-
-  void menu_sd_confirm() {
-    char * const longest = card.longest_filename();
-    char buffer[strlen(longest) + 2];
-    buffer[0] = ' ';
-    strcpy(buffer + 1, longest);
-    MenuItem_confirm::select_screen(
-      GET_TEXT(MSG_BUTTON_PRINT), GET_TEXT(MSG_BUTTON_CANCEL),
-      sdcard_start_selected_file, ui.goto_previous_screen,
-      GET_TEXT(MSG_START_PRINT), buffer, PSTR("?")
-    );
-  }
-
-#endif
-
 class MenuItem_sdfile : public MenuItem_sdbase {
   public:
     static inline void draw(const bool sel, const uint8_t row, PGM_P const pstr, CardReader &theCard) {
         sd_items = screen_items;
       #endif
       #if ENABLED(SD_MENU_CONFIRM_START)
-        MenuItem_submenu::action(pstr, menu_sd_confirm);
+        MenuItem_submenu::action(pstr, []{
+          char * const longest = card.longest_filename();
+          char buffer[strlen(longest) + 2];
+          buffer[0] = ' ';
+          strcpy(buffer + 1, longest);
+          MenuItem_confirm::select_screen(
+            GET_TEXT(MSG_BUTTON_PRINT), GET_TEXT(MSG_BUTTON_CANCEL),
+            sdcard_start_selected_file, ui.goto_previous_screen,
+            GET_TEXT(MSG_START_PRINT), buffer, PSTR("?")
+          );
+        });
       #else
         sdcard_start_selected_file();
         UNUSED(pstr);