ALSA: ASoC: Fix another cs4270 error path

Conversion to new-style i2c driver missed the error path of the
probe function. Fix it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Timur Tabi <timur@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>