Clean up planner modifier methods

Marlin/src/module/motion.cpp

   npos.e = planner.get_axis_position_mm(E_AXIS);
 
   #if HAS_POSITION_MODIFIERS
-    planner.unapply_modifiers(npos
-      #if HAS_LEVELING
-        , true
-      #endif
-    );
+    planner.unapply_modifiers(npos, true);
   #endif
 
   report_logical_position(npos);
   pos.e = planner.get_axis_position_mm(E_AXIS);
 
   #if HAS_POSITION_MODIFIERS
-    planner.unapply_modifiers(pos
-      #if HAS_LEVELING
-        , true
-      #endif
-    );
+    planner.unapply_modifiers(pos, true);
   #endif
 
   if (axis == ALL_AXES)

Marlin/src/module/planner.cpp

 void Planner::set_position_mm(const float &rx, const float &ry, const float &rz, const float &e) {
   xyze_pos_t machine = { rx, ry, rz, e };
   #if HAS_POSITION_MODIFIERS
-    apply_modifiers(machine
-      #if HAS_LEVELING
-        , true
-      #endif
-    );
+    apply_modifiers(machine, true);
   #endif
   #if IS_KINEMATIC
     position_cart.set(rx, ry, rz, e);

Marlin/src/module/planner.h

         unapply_leveling(raw);
         leveling_active = false;
       }
+    #else
+      FORCE_INLINE static void apply_leveling(xyz_pos_t&) {}
+      FORCE_INLINE static void unapply_leveling(xyz_pos_t&) {}
     #endif
 
     #if ENABLED(FWRETRACT)
     #endif
 
     #if HAS_POSITION_MODIFIERS
-      FORCE_INLINE static void apply_modifiers(xyze_pos_t &pos
-        #if HAS_LEVELING
-          , bool leveling = ENABLED(PLANNER_LEVELING)
-        #endif
-      ) {
+      FORCE_INLINE static void apply_modifiers(xyze_pos_t &pos, bool leveling=ENABLED(PLANNER_LEVELING)) {
         TERN_(SKEW_CORRECTION, skew(pos));
-        TERN_(HAS_LEVELING, if (leveling) apply_leveling(pos));
+        if (leveling) apply_leveling(pos);
         TERN_(FWRETRACT, apply_retract(pos));
       }
 
-      FORCE_INLINE static void unapply_modifiers(xyze_pos_t &pos
-        #if HAS_LEVELING
-          , bool leveling = ENABLED(PLANNER_LEVELING)
-        #endif
-      ) {
+      FORCE_INLINE static void unapply_modifiers(xyze_pos_t &pos, bool leveling=ENABLED(PLANNER_LEVELING)) {
         TERN_(FWRETRACT, unapply_retract(pos));
-        TERN_(HAS_LEVELING, if (leveling) unapply_leveling(pos));
+        if (leveling) unapply_leveling(pos);
         TERN_(SKEW_CORRECTION, unskew(pos));
       }
     #endif // HAS_POSITION_MODIFIERS