make block structure protected

[[Imported from SVN: r3321]]

dune/solvers/iterationsteps/linegsstep.hh

@@ -13,11 +13,13 @@ template<class OperatorType,
 
         typedef typename DiscFuncType::block_type VectorBlock;
 
+        enum {BlockSize = VectorBlock::dimension};
+
+    protected:
+
         // Describes the ordering of the degrees of freedom in 1d blocks
         std::vector<std::vector<unsigned int> > blockStructure_;
 
-        enum {BlockSize = VectorBlock::dimension};
-		
     public:
 		
         //! Default constructor.  Doesn't init anything