Clarify some motion code

Marlin/src/module/motion.cpp

@@ -70,16 +70,16 @@ bool relative_mode = false;
 /**
  * Cartesian Current Position
  *   Used to track the native machine position as moves are queued.
- *   Used by 'line_to_current_position' to do a move after changing it.
+ *   Used by 'buffer_line_to_current_position' to do a move after changing it.
  *   Used by 'SYNC_PLAN_POSITION_KINEMATIC' to update 'planner.position'.
  */
 float current_position[XYZE] = { 0.0 };
 
 /**
  * Cartesian Destination
- *   A temporary position, usually applied to 'current_position'.
- *   Set with 'get_destination_from_command' or 'set_destination_from_current'.
- *   'line_to_destination' sets 'current_position' to 'destination'.
+ *   The destination for a move, filled in by G-code movement commands,
+ *   and expected by functions like 'prepare_move_to_destination'.
+ *   Set with 'gcode_get_destination' or 'set_destination_from_current'.
  */
 float destination[XYZE] = { 0.0 };
 
@@ -235,7 +235,7 @@ void line_to_current_position() {
  * Move the planner to the position stored in the destination array, which is
  * used by G0/G1/G2/G3/G5 and many other functions to set a destination.
  */
-void line_to_destination(const float fr_mm_s) {
+void buffer_line_to_destination(const float fr_mm_s) {
   planner.buffer_line(destination[X_AXIS], destination[Y_AXIS], destination[Z_AXIS], destination[E_AXIS], fr_mm_s, active_extruder);
 }
 
@@ -667,7 +667,7 @@ float soft_endstop_min[XYZ] = { X_MIN_BED, Y_MIN_BED, Z_MIN_POS },
       }
     #endif // HAS_MESH
 
-    line_to_destination(MMS_SCALED(feedrate_mm_s));
+    buffer_line_to_destination(MMS_SCALED(feedrate_mm_s));
     return false;
   }