Fix cruft on kml scale output

src/ol/format/kmlformat.js

@@ -2484,7 +2484,9 @@ ol.format.KML.writePolyStyle_ = function(node, style, objectStack) {
  * @private
  */
 ol.format.KML.writeScaleTextNode_ = function(node, scale) {
-  ol.format.XSD.writeDecimalTextNode(node, scale * scale);
+  // the Math is to remove any excess decimals created by float arithmetic
+  ol.format.XSD.writeDecimalTextNode(node,
+      Math.round(scale * scale * 1e6) / 1e6);
 };