It's harmless but annyoing.
  sound/pci/hda/patch_realtek.c: In function ‘alc_cap_getput_caller’:
  sound/pci/hda/patch_realtek.c:2722:9: warning: ‘err’ may be used uninitialized in this function
Signed-off-by: Takashi Iwai <tiwai@suse.de>
 {
        struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
        struct alc_spec *spec = codec->spec;
-       int i, err;
+       int i, err = 0;
 
        mutex_lock(&codec->control_mutex);
        if (check_adc_switch && spec->dual_adc_switch) {