🔧 Fix X2/Y2 axis pins check

Author: thinkyhead

Marlin/src/inc/SanityCheck.h

@@ -239,15 +239,13 @@ static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _L
 /**
  * Multiple Stepper Drivers Per Axis
  */
-#define GOOD_AXIS_PINS(A) (HAS_##A##_ENABLE && HAS_##A##_STEP && HAS_##A##_DIR)
-#if HAS_X2_STEPPER && !GOOD_AXIS_PINS(X)
+#define GOOD_AXIS_PINS(A) PINS_EXIST(A##_ENABLE, A##_STEP, A##_DIR)
+#if HAS_X2_STEPPER && !GOOD_AXIS_PINS(X2)
   #error "If X2_DRIVER_TYPE is defined, then X2 ENABLE/STEP/DIR pins are also needed."
 #endif
-
-#if HAS_DUAL_Y_STEPPERS && !GOOD_AXIS_PINS(Y)
+#if HAS_DUAL_Y_STEPPERS && !GOOD_AXIS_PINS(Y2)
   #error "If Y2_DRIVER_TYPE is defined, then Y2 ENABLE/STEP/DIR pins are also needed."
 #endif
-
 #if HAS_Z_AXIS
   #if NUM_Z_STEPPERS >= 2 && !GOOD_AXIS_PINS(Z2)
     #error "If Z2_DRIVER_TYPE is defined, then Z2 ENABLE/STEP/DIR pins are also needed."