Replace target with destination in M600

Marlin/Marlin_main.cpp

    * M600: Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
    */
   inline void gcode_M600() {
-    float target[NUM_AXIS], lastpos[NUM_AXIS], fr60 = feedrate / 60;
+
     if (degHotend(active_extruder) < extrude_min_temp) {
       SERIAL_ERROR_START;
       SERIAL_ERRORLNPGM(MSG_TOO_COLD_FOR_M600);
       return;
     }
 
+    float lastpos[NUM_AXIS], fr60 = feedrate / 60;
+
     for (int i=0; i<NUM_AXIS; i++)
-      target[i] = lastpos[i] = current_position[i];
+      lastpos[i] = destination[i] = current_position[i];
 
-    #define BASICPLAN plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], fr60, active_extruder);
     #ifdef DELTA
-      #define RUNPLAN calculate_delta(target); BASICPLAN
+      #define RUNPLAN calculate_delta(destination); \
+                      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], destination[E_AXIS], fr60, active_extruder);
     #else
-      #define RUNPLAN BASICPLAN
+      #define RUNPLAN line_to_destination();
     #endif
 
     //retract by E
-    if (code_seen('E')) target[E_AXIS] += code_value();
+    if (code_seen('E')) destination[E_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_FIRSTRETRACT
-      else target[E_AXIS] += FILAMENTCHANGE_FIRSTRETRACT;
+      else destination[E_AXIS] += FILAMENTCHANGE_FIRSTRETRACT;
     #endif
 
     RUNPLAN;
 
     //lift Z
-    if (code_seen('Z')) target[Z_AXIS] += code_value();
+    if (code_seen('Z')) destination[Z_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_ZADD
-      else target[Z_AXIS] += FILAMENTCHANGE_ZADD;
+      else destination[Z_AXIS] += FILAMENTCHANGE_ZADD;
     #endif
 
     RUNPLAN;
 
     //move xy
-    if (code_seen('X')) target[X_AXIS] = code_value();
+    if (code_seen('X')) destination[X_AXIS] = code_value();
     #ifdef FILAMENTCHANGE_XPOS
-      else target[X_AXIS] = FILAMENTCHANGE_XPOS;
+      else destination[X_AXIS] = FILAMENTCHANGE_XPOS;
     #endif
 
-    if (code_seen('Y')) target[Y_AXIS] = code_value();
+    if (code_seen('Y')) destination[Y_AXIS] = code_value();
     #ifdef FILAMENTCHANGE_YPOS
-      else target[Y_AXIS] = FILAMENTCHANGE_YPOS;
+      else destination[Y_AXIS] = FILAMENTCHANGE_YPOS;
     #endif
 
     RUNPLAN;
 
-    if (code_seen('L')) target[E_AXIS] += code_value();
+    if (code_seen('L')) destination[E_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_FINALRETRACT
-      else target[E_AXIS] += FILAMENTCHANGE_FINALRETRACT;
+      else destination[E_AXIS] += FILAMENTCHANGE_FINALRETRACT;
     #endif
 
     RUNPLAN;
     #endif
           
     //return to normal
-    if (code_seen('L')) target[E_AXIS] -= code_value();
+    if (code_seen('L')) destination[E_AXIS] -= code_value();
     #ifdef FILAMENTCHANGE_FINALRETRACT
-      else target[E_AXIS] -= FILAMENTCHANGE_FINALRETRACT;
+      else destination[E_AXIS] -= FILAMENTCHANGE_FINALRETRACT;
     #endif
 
-    current_position[E_AXIS] = target[E_AXIS]; //the long retract of L is compensated by manual filament feeding
+    current_position[E_AXIS] = destination[E_AXIS]; //the long retract of L is compensated by manual filament feeding
     plan_set_e_position(current_position[E_AXIS]);
 
     RUNPLAN; //should do nothing
 
     #ifdef DELTA
       calculate_delta(lastpos);
-      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move xyz back
-      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder); //final untretract
+      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], destination[E_AXIS], fr60, active_extruder);
+      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder);
     #else
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], target[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move xy back
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], lastpos[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move z back
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], lastpos[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder); //final untretract
+      // Move XY to starting position, then Z, then E
+      destination[X_AXIS] = lastpos[X_AXIS];
+      destination[Y_AXIS] = lastpos[Y_AXIS];
+      line_to_destination();
+      destination[Z_AXIS] = lastpos[Z_AXIS];
+      line_to_destination();
+      destination[E_AXIS] = lastpos[E_AXIS];
+      line_to_destination();
     #endif        
 
     #ifdef FILAMENT_RUNOUT_SENSOR