Remove useless assignment in lcd_cooldown

The current filament action will be aborted by lcd_return_to_status()

Firmware/ultralcd.cpp

@@ -1399,7 +1399,6 @@ static void lcd_cooldown()
   setAllTargetHotends(0);
   setTargetBed(0);
   fanSpeed = 0;
-  eFilamentAction = FilamentAction::None;
   lcd_return_to_status();
 }