Minor stepper cleanup

Marlin/Marlin_main.cpp

     // When deploying make sure BLTOUCH is not already triggered
     #if ENABLED(BLTOUCH)
       if (deploy && TEST_BLTOUCH()) { stop(); return true; }
-    #endif
-
-    #if ENABLED(Z_PROBE_SLED)
+    #elif ENABLED(Z_PROBE_SLED)
       if (axis_unhomed_error(true, false, false)) { stop(); return true; }
     #elif ENABLED(Z_PROBE_ALLEN_KEY)
       if (axis_unhomed_error(true, true,  true )) { stop(); return true; }
     // Tell the planner where we actually are
     SYNC_PLAN_POSITION_KINEMATIC();
 
-
     #if ENABLED(DEBUG_LEVELING_FEATURE)
       if (DEBUGGING(LEVELING)) DEBUG_POS("<<< do_probe_move", current_position);
     #endif

Marlin/stepper.cpp

 
 #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
 
-  unsigned char Stepper::old_OCR0A = 0;
-  volatile unsigned char Stepper::eISR_Rate = 200; // Keep the ISR at a low rate until needed
+  uint8_t Stepper::old_OCR0A = 0;
+  volatile uint8_t Stepper::eISR_Rate = 200; // Keep the ISR at a low rate until needed
 
   #if ENABLED(LIN_ADVANCE)
     volatile int Stepper::e_steps[E_STEPPERS];
 
 void Stepper::isr() {
   if (cleaning_buffer_counter) {
+    --cleaning_buffer_counter;
     current_block = NULL;
     planner.discard_current_block();
     #ifdef SD_FINISHED_RELEASECOMMAND
-      if ((cleaning_buffer_counter == 1) && (SD_FINISHED_STEPPERRELEASE)) enqueue_and_echo_commands_P(PSTR(SD_FINISHED_RELEASECOMMAND));
+      if (!cleaning_buffer_counter && (SD_FINISHED_STEPPERRELEASE)) enqueue_and_echo_commands_P(PSTR(SD_FINISHED_RELEASECOMMAND));
     #endif
-    cleaning_buffer_counter--;
     OCR1A = 200; // Run at max speed - 10 KHz
     return;
   }
   #endif
 
   // Calculate new timer value
-  uint16_t timer, step_rate;
   if (step_events_completed <= (uint32_t)current_block->accelerate_until) {
 
     MultiU24X32toH16(acc_step_rate, acceleration_time, current_block->acceleration_rate);
     NOMORE(acc_step_rate, current_block->nominal_rate);
 
     // step_rate to timer interval
-    timer = calc_timer(acc_step_rate);
+    uint16_t timer = calc_timer(acc_step_rate);
     OCR1A = timer;
     acceleration_time += timer;
 
     #endif
   }
   else if (step_events_completed > (uint32_t)current_block->decelerate_after) {
+    uint16_t step_rate;
     MultiU24X32toH16(step_rate, deceleration_time, current_block->acceleration_rate);
 
     if (step_rate < acc_step_rate) { // Still decelerating?
       step_rate = current_block->final_rate;
 
     // step_rate to timer interval
-    timer = calc_timer(step_rate);
+    uint16_t timer = calc_timer(step_rate);
     OCR1A = timer;
     deceleration_time += timer;
 

Marlin/stepper.h

     static volatile uint32_t step_events_completed; // The number of step events executed in the current block
 
     #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
-      static unsigned char old_OCR0A;
-      static volatile unsigned char eISR_Rate;
+      static uint8_t old_OCR0A;
+      static volatile uint8_t eISR_Rate;
       #if ENABLED(LIN_ADVANCE)
         static volatile int e_steps[E_STEPPERS];
         static int final_estep_rate;