ASoC: adau1977: remove useless return

ASoC: adau1977: remove useless return

Cppcheck warning:

sound/soc/codecs/adau1977.c:242:9: warning: Identical condition and
return expression 'ret', return value is always 0
[identicalConditionAfterEarlyExit]

 return ret;
        ^
sound/soc/codecs/adau1977.c:239:6: note: If condition 'ret' is true,
the function will return/exit

 if (ret)
     ^
sound/soc/codecs/adau1977.c:242:9: note: Returning identical expression 'ret'
 return ret;
        ^

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210312182246.5153-4-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>