power: reset: zx-reboot: put device node in zx_reboot_probe()

zx_reboot_probe() increments refcnt of zx296702-pcu device node by
of_find_compatible_node() and leaves it undecremented on both
successful and error paths.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/power/reset/zx-reboot.c

@@ -51,6 +51,7 @@ static int zx_reboot_probe(struct platform_device *pdev)
 
 	np = of_find_compatible_node(NULL, NULL, "zte,zx296702-pcu");
 	pcu_base = of_iomap(np, 0);
+	of_node_put(np);
 	if (!pcu_base) {
 		iounmap(base);
 		WARN(1, "failed to map pcu_base address");