Fix M43 without watchdog (#15280)

Marlin/src/gcode/config/M43.cpp

@@ -50,6 +50,12 @@
   #define GET_PIN_MAP_PIN_M43(Q) GET_PIN_MAP_PIN(Q)
 #endif
 
+inline void _watchdog_reset() {
+  #if ENABLED(USE_WATCHDOG)
+    watchdog_reset();
+  #endif
+}
+
 inline void toggle_pins() {
   const bool ignore_protection = parser.boolval('I');
   const int repeat = parser.intval('R', 1),
@@ -65,7 +71,7 @@ inline void toggle_pins() {
       SERIAL_EOL();
     }
     else {
-      watchdog_reset();
+      _watchdog_reset();
       report_pin_state_extended(pin, ignore_protection, true, "Pulsing   ");
       #if AVR_AT90USB1286_FAMILY // Teensy IDEs don't know about these pins so must use FASTIO
         if (pin == TEENSY_E2) {
@@ -89,10 +95,10 @@ inline void toggle_pins() {
       {
         pinMode(pin, OUTPUT);
         for (int16_t j = 0; j < repeat; j++) {
-          watchdog_reset(); extDigitalWrite(pin, 0); safe_delay(wait);
-          watchdog_reset(); extDigitalWrite(pin, 1); safe_delay(wait);
-          watchdog_reset(); extDigitalWrite(pin, 0); safe_delay(wait);
-          watchdog_reset();
+          _watchdog_reset(); extDigitalWrite(pin, 0); safe_delay(wait);
+          _watchdog_reset(); extDigitalWrite(pin, 1); safe_delay(wait);
+          _watchdog_reset(); extDigitalWrite(pin, 0); safe_delay(wait);
+          _watchdog_reset();
         }
       }
     }