More fixes for xpcshell tests; seriously, where did people ever manage to discover this junk?

browser/components/privatebrowsing/test/browser/browser_privatebrowsing_commandline_toggle.js

@@ -51,7 +51,7 @@ function test() {
 
     testprivatecl.prototype = {
       _arguments: ["private-toggle"],
-      get length getLength() {
+      get length() {
         return this._arguments.length;
       },
       getArgument: function getArgument(aIndex) {

browser/components/privatebrowsing/test/unit/do_test_privatebrowsing_commandline.js

@@ -43,7 +43,7 @@ function testprivatecl() {
 
 testprivatecl.prototype = {
   _arguments: ["private", "silent"],
-  get length getLength() {
+  get length() {
     return this._arguments.length;
   },
   getArgument: function getArgument(aIndex) {