mfd: max77620: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c
index b1700b5..d821736 100644
--- a/drivers/mfd/max77620.c
+++ b/drivers/mfd/max77620.c
@@ -285,7 +285,7 @@
 	}
 
 	if (fps_id == MAX77620_FPS_COUNT) {
-		dev_err(dev, "FPS node name %s is not valid\n", fps_np->name);
+		dev_err(dev, "FPS node name %pOFn is not valid\n", fps_np);
 		return -EINVAL;
 	}