Shrink 3-point leveling code

Marlin/Marlin_main.cpp

@@ -3518,23 +3518,21 @@ inline void gcode_G28() {
       #endif
 
       // Probe at 3 arbitrary points
-      float z_at_pt_1 = probe_pt( LOGICAL_X_POSITION(ABL_PROBE_PT_1_X),
-                                  LOGICAL_Y_POSITION(ABL_PROBE_PT_1_Y),
-                                  stow_probe_after_each, verbose_level),
-            z_at_pt_2 = probe_pt( LOGICAL_X_POSITION(ABL_PROBE_PT_2_X),
-                                  LOGICAL_Y_POSITION(ABL_PROBE_PT_2_Y),
-                                  stow_probe_after_each, verbose_level),
-            z_at_pt_3 = probe_pt( LOGICAL_X_POSITION(ABL_PROBE_PT_3_X),
-                                  LOGICAL_Y_POSITION(ABL_PROBE_PT_3_Y),
-                                  stow_probe_after_each, verbose_level);
-
-      if (!dryrun) {
-        vector_3 pt1 = vector_3(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, z_at_pt_1),
-                 pt2 = vector_3(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, z_at_pt_2),
-                 pt3 = vector_3(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, z_at_pt_3);
+      vector_3 points[3] = {
+        vector_3(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, 0),
+        vector_3(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, 0),
+        vector_3(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, 0)
+      };
 
-        vector_3 planeNormal = vector_3::cross(pt1 - pt2, pt3 - pt2).get_normal();
+      for (uint8_t i = 0; i < 3; ++i)
+        points[i].z = probe_pt(
+          LOGICAL_X_POSITION(points[i].x),
+          LOGICAL_Y_POSITION(points[i].y),
+          stow_probe_after_each, verbose_level
+        );
 
+      if (!dryrun) {
+        vector_3 planeNormal = vector_3::cross(points[0] - points[1], points[2] - points[1]).get_normal();
         if (planeNormal.z < 0) {
           planeNormal.x *= -1;
           planeNormal.y *= -1;