macintosh: windfarm: use for_each_child_of_node() macro

Use for_each_child_of_node() macro instead of open coding it.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914061411.3356-1-miaoqinglang@huawei.com

drivers/macintosh/windfarm_smu_sat.c

@@ -216,8 +216,7 @@ static int wf_sat_probe(struct i2c_client *client,
 
 	vsens[0] = vsens[1] = -1;
 	isens[0] = isens[1] = -1;
-	child = NULL;
-	while ((child = of_get_next_child(dev, child)) != NULL) {
+	for_each_child_of_node(dev, child) {
 		reg = of_get_property(child, "reg", NULL);
 		loc = of_get_property(child, "location", NULL);
 		if (reg == NULL || loc == NULL)