QtSupport: Fix compilation with gcc.

Change-Id: I271072584882e256c7bfcbc39acdef0b42495bda
Reviewed-on: http://codereview.qt-project.org/6445
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@nokia.com>
Sanity-Review: Qt Sanity Bot <qt_sanity_bot@ovi.com>

src/plugins/qtsupport/gettingstartedwelcomepage.cpp

@@ -164,7 +164,8 @@ public:
 
         if (m_fetcher.data().isEmpty())
             return QImage();
-        QBuffer imgBuffer(&m_fetcher.data());
+        QByteArray data = m_fetcher.data();
+        QBuffer imgBuffer(&data);
         imgBuffer.open(QIODevice::ReadOnly);
         QImageReader reader(&imgBuffer);
         QImage img = reader.read();