message: Update tests/unit/fem/test_white_noise.cpp
  Commiting Veselin's suggestion
diff: @@ -206,7 +206,8 @@ TEST_CASE("Parallel WhiteGaussianNoiseDomainLFIntegrator on 2D NCMesh",
  a.FormSystemMatrix(empty,M);
  // Compare population covariance to mass matrix
  - HypreParMatrix * diff = Add(1., *ParC, -1., M);
  + M *= -1.;
  + HypreParMatrix * diff = ParAdd(ParC, &M);
  SparseMatrix diag, offd;
  diff->GetDiag(diag);
  