✏️ MMU2 followup (#24770)

Followup to #24750

Marlin/src/feature/mmu/mmu2.cpp

 
   void MMU2::mmu_continue_loading() {
     // Try to load the filament a limited number of times
+    bool fil_present = 0;
     for (uint8_t i = 0; i < MMU_LOADING_ATTEMPTS_NR; i++) {
       DEBUG_ECHOLNPGM("Load attempt #", i + 1);
 
       // Done as soon as filament is present
-      bool fil_present = FILAMENT_PRESENT();
+      fil_present = FILAMENT_PRESENT();
       if (fil_present) break;
 
       // Attempt to load the filament, 1mm at a time, for 3s

Marlin/src/feature/mmu/mmu2.h

   #endif
 
   #if ENABLED(MMU_EXTRUDER_SENSOR)
+    #define MMU_LOAD_FEEDRATE 19.02f // (mm/s)
     static void mmu_continue_loading();
   #endif