Fix some warnings

Author: m-kuhn

src/core/layertree/qgslayertreemodellegendnode.cpp

@@ -171,7 +171,8 @@ QVariant QgsSymbolV2LegendNode::data( int role ) const
       QPixmap pix;
       if ( mItem.symbol() )
       {
-        double scale, mupp = 0;
+        double scale = 0.0;
+        double mupp = 0.0;
         int dpi = 0;
         if ( model() )
           model()->legendMapViewData( &mupp, &dpi, &scale );

tests/src/core/testqgscomposerrotation.cpp

@@ -54,7 +54,6 @@ class TestQgsComposerRotation: public QObject
     QgsComposition* mComposition;
     QgsComposerShape* mComposerRect;
     QgsComposerLabel* mComposerLabel;
-    QgsMapRenderer* mMapRenderer;
     QgsComposerMap* mComposerMap;
     QgsMapSettings mMapSettings;
     QgsRasterLayer* mRasterLayer;

tests/src/core/testqgsgeometry.cpp

@@ -431,7 +431,7 @@ bool TestQgsGeometry::renderCheck( QString theTestName, QString theComment , int
   QgsRenderChecker myChecker;
   myChecker.setControlName( "expected_" + theTestName );
   myChecker.setRenderedImage( myFileName );
-  bool myResultFlag = myChecker.compareImages( theTestName );
+  bool myResultFlag = myChecker.compareImages( theTestName, mismatchCount );
   mReport += myChecker.report();
   return myResultFlag;
 }