ASoC: codecs: aw88261: avoid uninitialized variable warning

aw88261_reg_update() returns an unintialized error code in the
success path:

sound/soc/codecs/aw88261.c:651:7: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (aw_dev->prof_cur != aw_dev->prof_index) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/soc/codecs/aw88261.c:660:9: note: uninitialized use occurs here
return ret;
^~~
sound/soc/codecs/aw88261.c:651:3: note: remove the 'if' if its condition is always true
if (aw_dev->prof_cur != aw_dev->prof_index) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Return zero instead here.

Fixes: 028a2ae256916 ("ASoC: codecs: Add aw88261 amplifier driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230808125703.1611325-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>