Fix E direction for MK2_MULTIPLEXER with LIN_ADVANCE

Marlin/src/module/stepper.cpp

@@ -752,7 +752,7 @@ void Stepper::isr() {
   void Stepper::advance_isr() {
 
     #if ENABLED(MK2_MULTIPLEXER) // For SNMM even-numbered steppers are reversed
-      #define SET_E_STEP_DIR(INDEX) do{ if (e_steps) E## INDEX ##_DIR_WRITE(e_steps < 0 ? !INVERT_E## INDEX ##_DIR ^ TEST(INDEX, 0) : INVERT_E## INDEX ##_DIR ^ TEST(INDEX, 0)); }while(0)
+      #define SET_E_STEP_DIR(INDEX) do{ if (e_steps) E0_DIR_WRITE(e_steps < 0 ? !INVERT_E## INDEX ##_DIR ^ TEST(INDEX, 0) : INVERT_E## INDEX ##_DIR ^ TEST(INDEX, 0)); }while(0)
     #elif ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
       #define SET_E_STEP_DIR(INDEX) do{ if (e_steps) { if (e_steps < 0) REV_E_DIR(); else NORM_E_DIR(); } }while(0)
     #else