ALSA: hda - Fix misc compile warnings in patch_ca0132.c

  sound/pci/hda/patch_ca0132.c: In function ‘ca0132_is_vnode_effective’:
  sound/pci/hda/patch_ca0132.c:3331:15: warning: ‘nid’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  sound/pci/hda/patch_ca0132.c:4345:13: warning: ‘ca0132_download_dsp’ defined but not used [-Wunused-function]

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