gpio: brcmstb: Use local variable to access OF node

We already have a local variable that contains a copy of OF node pointer.
Use it instead of dereferencing it again from struct device.

Signed-off-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-brcmstb.c

···
 		}
 
 		gc->owner = THIS_MODULE;
-		gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", dev->of_node);
+		gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
 		if (!gc->label) {
 			err = -ENOMEM;
 			goto fail;