[ALSA] sun-cs4231: checkpatch fixes

This patch fixes white spaces and issues pointed by
the checkpatch.pl script.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>