Changed qxmlstream unittest to remove its created file after run.

- Removes test.xml after test completed.

Change-Id: I548e2d644cca8ae0d30c3002df45cf57433170af
Reviewed-by: Kurt Korbatits  <kurt.korbatits@nokia.com>
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>

tests/auto/corelib/xml/qxmlstream/tst_qxmlstream.cpp

@@ -532,6 +532,7 @@ public:
 
 private slots:
     void initTestCase();
+    void cleanupTestCase();
     void reportFailures() const;
     void reportFailures_data();
     void checkBaseline() const;
@@ -589,6 +590,11 @@ void tst_QXmlStream::initTestCase()
     QVERIFY(reader.parse(&source, false));
 }
 
+void tst_QXmlStream::cleanupTestCase()
+{
+    QFile::remove(QLatin1String("test.xml"));
+}
+
 void tst_QXmlStream::reportFailures() const
 {
     QFETCH(bool, isError);