iio: adc: adi-axi-adc: Fix refcount leak in adi_axi_adc_attach_client

of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: ef040706 ("iio: adc: adi-axi-adc: add support for AXI ADC IP core")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220524074517.45268-1-linmq006@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/adi-axi-adc.c

@@ -322,16 +322,19 @@ static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
 
 		if (!try_module_get(cl->dev->driver->owner)) {
 			mutex_unlock(&registered_clients_lock);
+			of_node_put(cln);
 			return ERR_PTR(-ENODEV);
 		}
 
 		get_device(cl->dev);
 		cl->info = info;
 		mutex_unlock(&registered_clients_lock);
+		of_node_put(cln);
 		return cl;
 	}
 
 	mutex_unlock(&registered_clients_lock);
+	of_node_put(cln);
 
 	return ERR_PTR(-EPROBE_DEFER);
 }