Use block cleaning instead of split flag

Marlin/src/module/stepper.cpp

@@ -1250,6 +1250,7 @@ void Stepper::endstop_triggered(AxisEnum axis) {
   #endif // !COREXY && !COREXZ && !COREYZ
 
   kill_current_block();
+  cleaning_buffer_counter = -(BLOCK_BUFFER_SIZE - 1); // Ignore remaining blocks
 }
 
 void Stepper::report_positions() {