ASoC: tas6424: Return zero in remove callback

The only effect of returning an error code in an i2c remove callback
(compared to returning zero) is that the i2c core emits a generic
warning. The device is still removed.

So even if disabling the regulators fails it's sensible to return zero
to suppress the additional generic and little helpful error message.

This patch is a preparation for making i2c remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220425193206.61710-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>