ASoC: adau17x1: remove unused ‘ret’

In adau17x1_pll_event(), 'ret' is initialized as return value of
regmap_raw_write() but never checked, so remove this and assignement.

sound/soc/codecs/adau17x1.c: In function ‘adau17x1_pll_event’:
sound/soc/codecs/adau17x1.c:68:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]
  int ret;

Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>