staging: vchiq_arm: add missing of_node_put

After device_node usage the refcount must be decremented with
of_node_put().
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -2900,6 +2900,7 @@ static int vchiq_probe(struct platform_device *pdev)
 	}
 
 	fw = rpi_firmware_get(fw_node);
+	of_node_put(fw_node);
 	if (!fw)
 		return -EPROBE_DEFER;