Some cleanup ahead of BLTOUCH support

Marlin/stepper.cpp

@@ -359,11 +359,11 @@ void Stepper::isr() {
   if (current_block) {
 
     // Update endstops state, if enabled
+    if (endstops.enabled
       #if HAS_BED_PROBE
-      if (endstops.enabled || endstops.z_probe_enabled) endstops.update();
+        || endstops.z_probe_enabled
-    #else
-      if (endstops.enabled) endstops.update();
       #endif
+    ) endstops.update();
 
     // Take multiple steps per interrupt (For high speed moves)
     for (int8_t i = 0; i < step_loops; i++) {