Shared singlenozzle item

Marlin/src/lcd/menu/menu_item.h

@@ -479,4 +479,14 @@ class MenuItem_bool : public MenuEditItemBase {
 
   #define SNFAN(N) (ENABLED(SINGLENOZZLE_STANDBY_FAN) && !HAS_FAN##N && EXTRUDERS > N)
 
+  #if SNFAN(1) || SNFAN(2) || SNFAN(3) || SNFAN(4) || SNFAN(5) || SNFAN(6) || SNFAN(7)
+    #define DEFINE_SINGLENOZZLE_ITEM() \
+      auto singlenozzle_item = [&](const uint8_t f) { \
+        editable.uint8 = singlenozzle_fan_speed[f]; \
+        EDIT_ITEM_FAST_N(percent, f, MSG_STORED_FAN_N, &editable.uint8, 0, 255, on_fan_update); \
+      }
+  #else
+    #define DEFINE_SINGLENOZZLE_ITEM() NOOP
+  #endif
+
 #endif // HAS_FAN

Marlin/src/lcd/menu/menu_temperature.cpp

@@ -191,12 +191,7 @@ void menu_temperature() {
   //
   #if HAS_FAN
 
-    #if SNFAN(1) || SNFAN(2) || SNFAN(3) || SNFAN(4) || SNFAN(5) || SNFAN(6) || SNFAN(7)
+    DEFINE_SINGLENOZZLE_ITEM();
-      auto singlenozzle_item = [&](const uint8_t f) {
-        editable.uint8 = singlenozzle_fan_speed[f];
-        EDIT_ITEM_FAST_N(percent, f, MSG_STORED_FAN_N, &editable.uint8, 0, 255, on_fan_update);
-      };
-    #endif
 
     #if HAS_FAN0
       _FAN_EDIT_ITEMS(0,FIRST_FAN_SPEED);

Marlin/src/lcd/menu/menu_tune.cpp

@@ -142,12 +142,7 @@ void menu_tune() {
   //
   #if HAS_FAN
 
-    #if SNFAN(1) || SNFAN(2) || SNFAN(3) || SNFAN(4) || SNFAN(5) || SNFAN(6) || SNFAN(7)
+    DEFINE_SINGLENOZZLE_ITEM();
-      auto singlenozzle_item = [&](const uint8_t f) {
-        editable.uint8 = singlenozzle_fan_speed[f];
-        EDIT_ITEM_FAST_N(percent, f, MSG_STORED_FAN_N, &editable.uint8, 0, 255, on_fan_update);
-      };
-    #endif
 
     #if HAS_FAN0
       _FAN_EDIT_ITEMS(0,FIRST_FAN_SPEED);