localadolcstiffness.hh: Remove RT, it is ayways "double"

dune/elasticity/assemblers/localadolcstiffness.hh

@@ -24,7 +24,6 @@ class LocalADOLCStiffness
 {
     // grid types
     typedef typename GridView::Grid::ctype DT;
-    typedef typename VectorType::value_type::field_type RT;
     typedef typename GridView::template Codim<0>::Entity Entity;
 
     // some other sizes
@@ -43,7 +42,7 @@ public:
     {}
 
     /** \brief Compute the energy at the current configuration */
-    virtual RT energy (const Entity& e,
+    virtual double energy (const Entity& e,
                const LocalFiniteElement& localFiniteElement,
                const VectorType& localConfiguration) const;
 
@@ -62,8 +61,7 @@ public:
 
 
 template <class GridView, class LocalFiniteElement, class VectorType>
-typename LocalADOLCStiffness<GridView, LocalFiniteElement, VectorType>::RT
-LocalADOLCStiffness<GridView, LocalFiniteElement, VectorType>::
+double LocalADOLCStiffness<GridView, LocalFiniteElement, VectorType>::
 energy(const Entity& element,
        const LocalFiniteElement& localFiniteElement,
        const VectorType& localSolution) const