ALSA: aw2: Use snd_ctl_enum_info()

... and reduce the open codes.  Also add missing const to the text array.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/aw2/aw2-alsa.c

@@ -725,19 +725,10 @@ static int snd_aw2_new_pcm(struct aw2 *chip)
 static int snd_aw2_control_switch_capture_info(struct snd_kcontrol *kcontrol,
 					       struct snd_ctl_elem_info *uinfo)
 {
-	static char *texts[2] = {
+	static const char * const texts[2] = {
 		"Analog", "Digital"
 	};
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
-	uinfo->count = 1;
-	uinfo->value.enumerated.items = 2;
-	if (uinfo->value.enumerated.item >= uinfo->value.enumerated.items) {
-		uinfo->value.enumerated.item =
-		    uinfo->value.enumerated.items - 1;
-	}
-	strcpy(uinfo->value.enumerated.name,
-	       texts[uinfo->value.enumerated.item]);
-	return 0;
+	return snd_ctl_enum_info(uinfo, 1, 2, texts);
 }
 
 static int snd_aw2_control_switch_capture_get(struct snd_kcontrol *kcontrol,