Fix Coverity warning

ogr/ogrgeometryfactory.cpp

@@ -2052,7 +2052,7 @@ OGRGeometry *OGRGeometryFactory::organizePolygons(OGRGeometry **papoPolygons,
                                     // j.
                                     break;
                                 }
-                                previousPoint = point;
+                                previousPoint = std::move(point);
                             }
                         }
                     }