Merge pull request #4276 from esenapaj/Suppress-warnings

Suppress warnings

Marlin/MarlinSerial.cpp

             case state_M410:
               quickstop_stepper();
               break;
+            default:
+              break;
           }
           state = state_RESET;
         }

Marlin/Marlin_main.cpp

    * Use either 'M421 X<linear> Y<linear> Z<linear>' or 'M421 I<xindex> J<yindex> Z<linear>'
    */
   inline void gcode_M421() {
-    int8_t px, py;
+    int8_t px = 0, py = 0;
     float z = 0;
     bool hasX, hasY, hasZ, hasI, hasJ;
     if ((hasX = code_seen('X'))) px = mbl.probe_index_x(code_value_axis_units(X_AXIS));
     disable_e3();
     delay(100);
 
-    millis_t next_tick = 0;
+    #if HAS_BUZZER
+      millis_t next_tick = 0;
+    #endif
 
     // Wait for filament insert by user and press button
     lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_INSERT);

Marlin/planner.cpp

   #endif
 
   #if ENABLED(BARICUDA)
-    unsigned char tail_valve_pressure = baricuda_valve_pressure,
-                  tail_e_to_p_pressure = baricuda_e_to_p_pressure;
+    #if HAS_HEATER_1
+      unsigned char tail_valve_pressure = baricuda_valve_pressure;
+    #endif
+    #if HAS_HEATER_2
+      unsigned char tail_e_to_p_pressure = baricuda_e_to_p_pressure;
+    #endif
   #endif
 
   if (blocks_queued()) {
 
     #if ENABLED(BARICUDA)
       block = &block_buffer[block_buffer_tail];
-      tail_valve_pressure = block->valve_pressure;
-      tail_e_to_p_pressure = block->e_to_p_pressure;
+      #if HAS_HEATER_1
+        tail_valve_pressure = block->valve_pressure;
+      #endif
+      #if HAS_HEATER_2
+        tail_e_to_p_pressure = block->e_to_p_pressure;
+      #endif
     #endif
 
     for (uint8_t b = block_buffer_tail; b != block_buffer_head; b = next_block_index(b)) {

Marlin/ultralcd.cpp

     for (int8_t _lcdLineNr = 0; _lcdLineNr < LCD_HEIGHT; _lcdLineNr++, _menuLineNr++) { \
       _thisItemNr = 0;
 
-  #define START_SCREEN() _START_SCREEN(0)
+  #define START_SCREEN() _START_SCREEN(NOOP)
 
   /**
    * START_MENU generates the init code for a menu function