Use for_each_compatible_node() macro.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/platforms/xtfpga/setup.c b/arch/xtensa/platforms/xtfpga/setup.c
index 71d61ca6..237c36d 100644
--- a/arch/xtensa/platforms/xtfpga/setup.c
+++ b/arch/xtensa/platforms/xtfpga/setup.c
@@ -105,9 +105,9 @@
 
 static int __init machine_setup(void)
 {
-	struct device_node *serial = NULL;
+	struct device_node *serial;
 
-	while ((serial = of_find_compatible_node(serial, NULL, "ns16550a")))
+	for_each_compatible_node(serial, NULL, "ns16550a")
 		update_clock_frequency(serial);
 	return 0;
 }