ALSA: aoa: Fix of-node refcount unbalance

We forgot to unreference a node obtained via of_find_node_by_name()
after its usage.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/aoa/core/gpio-feature.c

@@ -82,6 +82,7 @@ static struct device_node *get_gpio(char *name,
 			if (altname && (strcmp(audio_gpio, altname) == 0))
 				break;
 		}
+		of_node_put(gpio);
 		/* still not found, assume not there */
 		if (!np)
 			return NULL;