ALSA: snd-aoa: add of_node_put() in error path

BugLink: https://bugs.launchpad.net/bugs/1798770

[ Upstream commit 222bce5e ]

 Both calls to of_find_node_by_name() and of_get_next_child() return a
node pointer with refcount incremented thus it must be explicidly
decremented here after the last usage. As we are assured to have a
refcounted  np  either from the initial
of_find_node_by_name(NULL, name); or from the of_get_next_child(gpio, np)
in the while loop if we reached the error code path below, an
x of_node_put(np) is needed.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: commit f3d9478b ("[ALSA] snd-aoa: add snd-aoa")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

sound/aoa/core/gpio-feature.c

@@ -88,8 +88,10 @@ static struct device_node *get_gpio(char *name,
 	}
 
 	reg = of_get_property(np, "reg", NULL);
-	if (!reg)
+	if (!reg) {
+		of_node_put(np);
 		return NULL;
+	}
 
 	*gpioptr = *reg;