ASoC: codecs: wcd938x: fix mbhc impedance loglevel

Demote the MBHC impedance measurement printk, which is not an error
message, from error to debug level.

While at it, fix the capitalisation of "ohm" and add the missing space
before the opening parenthesis.

Fixes: bcee7ed0

 ("ASoC: codecs: wcd938x: add Multi Button Headset Control support")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230630142717.5314-2-johan+linaro@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>