ASoC: codecs: wcd938x: drop unnecessary mux flag assignment

The codec driver data is allocated using kzalloc() so there's no need to
clear the mux setup flag when mux selection fails during probe.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://patch.msgid.link/20250415074145.7202-3-johan+linaro@kernel.org


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