Fixing examplefor dense matrix.

template< typename Device >

void getCompressedRowLengthsExample()

{

   TNL::Matrices::DenseMatrix< double, Device > triangularMatrix {

   TNL::Matrices::DenseMatrix< double, Device > denseMatrix {

      {  1 },

      {  2,  3 },

      {  4,  5,  6 },

      {  7,  8,  9, 10 },

      { 11, 12, 13, 14, 15 }

   };

   auto triangularMatrixView = triangularMatrix.getConstView();

   auto denseMatrixView = denseMatrix.getConstView();

   std::cout << triangularMatrixView << std::endl;

   std::cout << denseMatrixView << std::endl;

   TNL::Containers::Vector< int, Device > rowLengths;

   triangularMatrixView.getCompressedRowLengths( rowLengths );

   denseMatrixView.getCompressedRowLengths( rowLengths );

   std::cout << "Compressed row lengths are: " << rowLengths << std::endl;

}