Add append_dmi_string() function and make the code more readable.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191120174435.30920-1-perex@perex.cz
Signed-off-by: Mark Brown <broonie@kernel.org>