message: fix single-precision dpcpp dense kernel tests
diff: @@ -215,7 +215,7 @@ TEST_F(Dense, CopyRespectsStride)
  set_up_vector_data(3);
  auto stride = dx->get_size()[1] + 1;
  auto result = Mtx::create(exec, dx->get_size(), stride);
  - double val = 123456789.0;
  + vtype val = 1234567.0;
  auto original_data = result->get_values();
  auto padding_ptr = original_data + dx->get_size()[1];
  exec->copy_from(ref.get(), 1, &val, padding_ptr);
  @@ -244,7 +244,7 @@ TEST_F(Dense, FillIsEquivalentToRef)
  TEST_F(Dense, StridedFillIsEquivalentToRef)
  {
  - using T = double;
  + using T = vtype;
  auto x = gko::initialize<gko::matrix::Dense<T>>(
  4, {I<T>{1.0, 2.0}, I<T>{3.0, 4.0}, I<T>{5.0, 6.0}}, ref);
  auto dx = gko::initialize<gko::matrix::Dense<T>>(
  