Minor Coverity fixes

Author: nyalldawson

src/app/nodetool/qgsmaptoolnodetool.h

@@ -120,9 +120,6 @@ class QgsMapToolNodeTool: public QgsMapToolEdit
     /** Dock widget which allows to edit vertices */
     QgsNodeEditor* mNodeEditor;
 
-    /** Feature id of another feature where user clicked */
-    QgsFeatureId mAnother;
-
     /** Stored position of last press down action to count how much vertexes should be moved */
     QPoint mPressCoordinates;
 

src/core/geometry/qgsgeometry.cpp

@@ -109,7 +109,7 @@ void QgsGeometry::detach( bool cloneGeom )
 
   if ( d->ref > 1 )
   {
-    d->ref.deref();
+    ( void )d->ref.deref();
     QgsAbstractGeometryV2* cGeom = 0;
 
     if ( d->geometry && cloneGeom )

src/gui/qgsgeometryrubberband.cpp

@@ -73,7 +73,7 @@ void QgsGeometryRubberBand::paint( QPainter* painter )
 
 void QgsGeometryRubberBand::drawVertex( QPainter* p, double x, double y )
 {
-  qreal s = ( mIconSize - 1 ) / 2;
+  qreal s = ( mIconSize - 1 ) / 2.0;
 
   switch ( mIconType )
   {