ASoC: nau8821: check regmap_raw_read/regmap_raw_write for failure

The return values from both regmap_raw_read() and regmap_raw_write() are not
checked despite they can fail. Propagate possible errors to caller.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Signed-off-by: Vitaliy Shevtsov <v.shevtsov@maxima.ru>
Link: https://patch.msgid.link/20241018110743.18786-1-v.shevtsov@maxima.ru


Signed-off-by: Mark Brown <broonie@kernel.org>