winrt: Initialize status and position tokens' values in constructor

Doing their initialization near the end of init() is too late because
parts of init (namely setUpdateInterval and
setPreferredPositioningMethods) rely on them.

Change-Id: I81ea1db53aa531248f2c49b8f53f2c33b5fb954e
Reviewed-by: Miguel Costa <miguel.costa@qt.io>

src/plugins/position/winrt/qgeopositioninfosource_winrt.cpp

@@ -132,6 +132,8 @@ QGeoPositionInfoSourceWinRT::QGeoPositionInfoSourceWinRT(QObject *parent)
     Q_D(QGeoPositionInfoSourceWinRT);
     d->positionError = QGeoPositionInfoSource::NoError;
     d->updatesOngoing = false;
+    d->positionToken.value = 0;
+    d->statusToken.value = 0;
 }
 
 QGeoPositionInfoSourceWinRT::~QGeoPositionInfoSourceWinRT()
@@ -173,9 +175,6 @@ int QGeoPositionInfoSourceWinRT::init()
         return -1;
     }
 
-    d->positionToken.value = 0;
-    d->statusToken.value = 0;
-
     d->periodicTimer.setSingleShot(true);
     connect(&d->periodicTimer, &QTimer::timeout, this, &QGeoPositionInfoSourceWinRT::virtualPositionUpdate);