[PATCH v2 1/8] Adjust util_is_printable_string() comment and fix test

[Jon Loeliger]

> This commit which changed the behaviour of this function broke one
> of the tests. Also the comment should be updated to reflect its new
> behaviour.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> Changes in v2:
> - Add new test to check byte output of a string list property

Applied.

Thanks,
jdl