ALSA: hda/ca0132 - Avoid division by zero in dspxfr_one_seg()

Move the zero check `hda_frame_size_words == 0' before the modulus
`buffer_size_words % hda_frame_size_words'.

Also remove the redundant null check `buffer_addx == NULL'.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>