When using YNL in tests appending the doc string to the type name makes it harder to check that we got the correct error. Put the doc under a separate key. Reviewed-by: Donald Hunter <donald.hunter@gmail.com> Link: https://lore.kernel.org/r/20240426003111.359285-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>