message: fix compilation issues due to missing cast
diff: @@ -118,10 +118,11 @@ protected:
  {0., 0., 9., -9.},
  {-2., -2., -9., 29.}},
  ref)),
  - mtx_l_init_expect(gko::initialize<Csr>({{3., 0., 0., 0.},
  + mtx_l_init_expect(gko::initialize<Csr>(
  + {{3., 0., 0., 0.},
  {0., 1., 0., 0.},
  - {-6., 18., sqrt(17.), 0.},
  - {-3., 24., 14., sqrt(18.)}},
  + {-6., 18., static_cast<value_type>(sqrt(17.)), 0.},
  + {-3., 24., 14., static_cast<value_type>(sqrt(18.))}},
  ref)),
  mtx_l_add_expect(gko::initialize<Csr>({{1., 0., 0., 0.},
  {1., 2., 0., 0.},
  @@ -133,10 +134,11 @@ protected:
  {-2., 3., 2., 0.},
  {-1., 4., 0., 1.}},
  ref)),
  - mtx_l_small_expect(gko::initialize<Csr>({{3., 0., 0., 0.},
  + mtx_l_small_expect(gko::initialize<Csr>(
  + {{3., 0., 0., 0.},
  {0., 6., 0., 0.},
  {-2., 3., 2., 0.},
  - {0., 4., 0., sqrt(2.)}},
  + {0., 4., 0., static_cast<value_type>(sqrt(2.))}},
  ref)),
  mtx_l_large_expect(gko::initialize<Csr>({{3., 0., 0., 0.},
  {0., 6., 0., 0.},
  