Backlash cleanup (#13659)

…And save backlash, fil. sensor, ExtUI userdata to EEPROM.

Marlin/src/feature/runout.h

@@ -78,6 +78,11 @@ class TFilamentMonitor : public FilamentMonitorBase {
       response.filament_present(extruder);
     }
 
+    #ifdef FILAMENT_RUNOUT_DISTANCE_MM
+      static inline float& runout_distance() { return response.runout_distance_mm; }
+      static inline void set_runout_distance(const float &mm) { response.runout_distance_mm = mm; }
+    #endif
+
     // Handle a block completion. RunoutResponseDelayed uses this to
     // add up the length of filament moved while the filament is out.
     static inline void block_completed(const block_t* const b) {
@@ -90,13 +95,13 @@ class TFilamentMonitor : public FilamentMonitorBase {
     // Give the response a chance to update its counter.
     static inline void run() {
       if (enabled && !filament_ran_out && (IS_SD_PRINTING() || print_job_timer.isRunning() || did_pause_print)) {
-        #if FILAMENT_RUNOUT_DISTANCE_MM > 0
+        #ifdef FILAMENT_RUNOUT_DISTANCE_MM
           cli(); // Prevent RunoutResponseDelayed::block_completed from accumulating here
         #endif
         response.run();
         sensor.run();
         const bool ran_out = response.has_run_out();
-        #if FILAMENT_RUNOUT_DISTANCE_MM > 0
+        #ifdef FILAMENT_RUNOUT_DISTANCE_MM
           sei();
         #endif
         if (ran_out) {
@@ -272,7 +277,7 @@ class FilamentSensorBase {
 
 /********************************* RESPONSE TYPE *********************************/
 
-#if FILAMENT_RUNOUT_DISTANCE_MM > 0
+#ifdef FILAMENT_RUNOUT_DISTANCE_MM
 
   // RunoutResponseDelayed triggers a runout event only if the length
   // of filament specified by FILAMENT_RUNOUT_DISTANCE_MM has been fed
@@ -347,11 +352,12 @@ class FilamentSensorBase {
 /********************************* TEMPLATE SPECIALIZATION *********************************/
 
 typedef TFilamentMonitor<
-  #if FILAMENT_RUNOUT_DISTANCE_MM > 0
+  #ifdef FILAMENT_RUNOUT_DISTANCE_MM
+    RunoutResponseDelayed,
     #if ENABLED(FILAMENT_MOTION_SENSOR)
-      RunoutResponseDelayed, FilamentSensorEncoder
+      FilamentSensorEncoder
     #else
-      RunoutResponseDelayed, FilamentSensorSwitch
+      FilamentSensorSwitch
     #endif
   #else
     RunoutResponseDebounced, FilamentSensorSwitch