Implement PositiveTensorFiniteElement::GetFaceMap

Factor out logic in NodalTensorFiniteElement::GetFaceMap to
GetNodalTensorFaceMap, reuse for the case of Bernstein basis.

fem/fe/fe_pos.cpp

@@ -12,6 +12,7 @@
 // H1 Finite Element classes utilizing the Bernstein basis
 
 #include "fe_pos.hpp"
+#include "face_map_utils.hpp"
 #include "../bilininteg.hpp"
 #include "../lininteg.hpp"
 #include "../coefficient.hpp"
@@ -84,6 +85,12 @@ PositiveTensorFiniteElement::PositiveTensorFiniteElement(
                            dims > 1 ? FunctionSpace::Qk : FunctionSpace::Pk),
      TensorBasisElement(dims, p, BasisType::Positive, dmtype) { }
 
+void PositiveTensorFiniteElement::GetFaceMap(const int face_id,
+                                             Array<int> &face_map) const
+{
+   GetNodalTensorFaceMap(dim, order, face_id, face_map);
+}
+
 
 BiQuadPos2DFiniteElement::BiQuadPos2DFiniteElement()
    : PositiveFiniteElement(2, Geometry::SQUARE, 9, 2, FunctionSpace::Qk)