Simplify a drivers.h macro (#16589)

Marlin/src/core/drivers.h

 #define AXIS_DRIVER_TYPE_X(T) _AXIS_DRIVER_TYPE(X,T)
 #define AXIS_DRIVER_TYPE_Y(T) _AXIS_DRIVER_TYPE(Y,T)
 #define AXIS_DRIVER_TYPE_Z(T) _AXIS_DRIVER_TYPE(Z,T)
-#define AXIS_DRIVER_TYPE_X2(T) (EITHER(X_DUAL_STEPPER_DRIVERS, DUAL_X_CARRIAGE) && _AXIS_DRIVER_TYPE(X2,T))
+#if EITHER(X_DUAL_STEPPER_DRIVERS, DUAL_X_CARRIAGE)
+  #define AXIS_DRIVER_TYPE_X2(T) _AXIS_DRIVER_TYPE(X2,T)
+#else
+  #define AXIS_DRIVER_TYPE_X2(T) false
+#endif
 #define AXIS_DRIVER_TYPE_Y2(T) (ENABLED(Y_DUAL_STEPPER_DRIVERS) && _AXIS_DRIVER_TYPE(Y2,T))
 #define AXIS_DRIVER_TYPE_Z2(T) (Z_MULTI_STEPPER_DRIVERS && _AXIS_DRIVER_TYPE(Z2,T))
 #define AXIS_DRIVER_TYPE_Z3(T) (ENABLED(Z_TRIPLE_STEPPER_DRIVERS) && _AXIS_DRIVER_TYPE(Z3,T))