🚸 G42 P as flag (not bool)

Marlin/src/gcode/bedlevel/G42.cpp

@@ -37,7 +37,7 @@
  *   F<feedrate> : Feedrate in mm/min
  *   I<index>    : X axis point index
  *   J<index>    : Y axis point index
- *   P<bool>     : Flag to put the prove at the given point
+ *   P           : Flag to put the probe at the given point
  */
 void GcodeSuite::G42() {
   if (MOTION_CONDITIONS) {
@@ -58,7 +58,7 @@ void GcodeSuite::G42() {
     if (hasJ) destination.y = bedlevel.get_mesh_y(iy);
 
     #if HAS_PROBE_XY_OFFSET
-      if (parser.boolval('P')) {
+      if (parser.seen_test('P')) {
         if (hasI) destination.x -= probe.offset_xy.x;
         if (hasJ) destination.y -= probe.offset_xy.y;
       }