ASoC: rt712-sdca: fix coding style and unconditionally return issues

This patch fixes
1. coding style issues
2. check if the setting was set already in rt712_sdca_mux_put callback

Signed-off-by: Shuming Fan <shumingf@realtek.com>
Link: https://lore.kernel.org/r/20230210082141.24077-1-shumingf@realtek.com


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