message: fix hip sellp test
diff: @@ -330,14 +330,8 @@ TEST_F(Sellp, ExtractDiagonalIsEquivalentToRef)
  {
  set_up_apply_matrix();
  - auto diag_size = std::min(mtx->get_size()[0], mtx->get_size()[1]);
  -
  - auto diag = gko::matrix::Dense<>::create(mtx->get_executor(),
  - gko::dim<2>(diag_size, 1));
  - auto ddiag = gko::matrix::Dense<>::create(dmtx->get_executor(),
  - gko::dim<2>(diag_size, 1));
  - mtx->extract_diagonal(lend(diag));
  - dmtx->extract_diagonal(lend(ddiag));
  + auto diag = mtx->extract_diagonal();
  + auto ddiag = dmtx->extract_diagonal();
  GKO_ASSERT_MTX_NEAR(diag.get(), ddiag.get(), 0);
  }
  