ALSA: cs4232: fix crash during chip PNP detection

The acard->wss pointer is uninitialized in this function
which leads to crash during chip PNP detection.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>