message: Simplify FillI() for face DG.
diff: @@ -347,6 +347,7 @@ void ElementRestriction::FillJandData(const Vector &ea_data,
  auto d_indices = indices.Read();
  auto d_gatherMap = gatherMap.Read();
  auto mat_ea = Reshape(ea_data.Read(), elt_dofs, elt_dofs, ne);
  + //TODO parallelize on i_L?
  MFEM_FORALL(e, ne,
  {
  constexpr int MaxNbNbr = 16;//TODO remove magic number
  @@ -1283,10 +1284,8 @@ void L2FaceRestriction::FillI(SparseMatrix &mat) const
  auto I = mat.ReadWriteI();
  MFEM_FORALL(fdof, nf*face_dofs,
  {
  - const int f = fdof/face_dofs;
  - const int iF = fdof%face_dofs;
  - const int iE1 = d_indices1[f*face_dofs+iF];
  - const int iE2 = d_indices2[f*face_dofs+iF];
  + const int iE1 = d_indices1[fdof];
  + const int iE2 = d_indices2[fdof];
  AddNnz(iE1,I,face_dofs);
  AddNnz(iE2,I,face_dofs);
  });
  