Remove redundant assignment in QXmlStreamReader

Setting tos to 0 once should be enough for everyone.

Task-number: QTBUG-20482
Change-Id: I7aa46ff5d4ed8064e3fb2cebc3dfcaa4e73741f8
Reviewed-on: http://codereview.qt-project.org/6053
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/corelib/xml/qxmlstream.cpp

@@ -808,7 +808,6 @@ QXmlStreamReaderPrivate::QXmlStreamReaderPrivate(QXmlStreamReader *q)
 
 void QXmlStreamReaderPrivate::init()
 {
-    tos = 0;
     scanDtd = false;
     token = -1;
     token_char = 0;