ASoC: Intel: kbl_da7219_max98927: test return value on route add

Fix cppcheck warning:

[sound/soc/intel/boards/kbl_da7219_max98927.c:340] ->
[sound/soc/intel/boards/kbl_da7219_max98927.c:348]: (style) Variable
'ret' is reassigned a value before the old one has been used.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200113210428.27457-7-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/kbl_da7219_max98927.c

@@ -341,6 +341,9 @@ static int kabylake_da7219_codec_init(struct snd_soc_pcm_runtime *rtd)
 			kabylake_ssp1_map,
 			ARRAY_SIZE(kabylake_ssp1_map));
 
+	if (ret)
+		return ret;
+
 	/*
 	 * Headset buttons map to the google Reference headset.
 	 * These can be configured by userspace.