generated dofmap code uses double when it should be an int

[Garth Wells]

The input

    P2 = VectorElement("Lagrange", triangle, 1)
    real = FiniteElement("Real", triangle, 0)
   element = P2 * real

creates a function

  /// Initialize dofmap for mesh (return true iff init_cell() is needed)
  virtual bool init_mesh(const ufc::mesh& m)
  {
    _global_dimension = 2.0*m.num_entities[0] + 1;
    return false;
  }

2.0 should be 2.