ALSA: cs4281: Fix missing chip initialization

The chip variable was forgotten to be initialized properly while
changing the object creation from the own malloc to
card->private_data.  This patch fixes it.

Fixes: 99041fea ("ALSA: cs4281: Allocate resources with device-managed APIs")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/s5him14ocjz.wl-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/cs4281.c

@@ -1288,7 +1288,7 @@ static int snd_cs4281_create(struct snd_card *card,
 			     struct pci_dev *pci,
 			     int dual_codec)
 {
-	struct cs4281 *chip;
+	struct cs4281 *chip = card->private_data;
 	int err;
 
 	err = pcim_enable_device(pci);