Multi-line comments cleanup (#19535)

Marlin/src/feature/mmu2/mmu2.cpp

@@ -710,13 +710,11 @@ void MMU2::tool_change(const uint8_t index) {
 }
 
 /**
- *
  * Handle special T?/Tx/Tc commands
  *
  * T? Gcode to extrude shouldn't have to follow, load to extruder wheels is done automatically
  * Tx Same as T?, except nozzle doesn't have to be preheated. Tc must be placed after extruder nozzle is preheated to finish filament load.
  * Tc Load to nozzle after filament was prepared by Tx and extruder nozzle is already heated.
- *
  */
 void MMU2::tool_change(const char* special) {
   if (!enabled) return;
@@ -922,9 +920,7 @@ void MMU2::filament_runout() {
   }
 
   /**
-   *
    * Switch material and load to nozzle
-   *
    */
   bool MMU2::load_filament_to_nozzle(const uint8_t index) {