ALSA: hda: tas2781-spi: Delete some dead code

The scnprintf() function never returns negatives.  And it won't return
zero here either, plus if it did we'd need to fix the error code.
Delete this dead code.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/d57ded9e-9969-4922-8347-67b758499483@stanley.mountain


Signed-off-by: Takashi Iwai <tiwai@suse.de>