pinctrl: microchip-sgpio: Put fwnode in error case during ->probe()

device_for_each_child_node() bumps a reference counting of a returned variable.
We have to balance it whenever we return to the caller.

Fixes: 7e5ea974e61c ("pinctrl: pinctrl-microchip-sgpio: Add pinctrl driver for Microsemi Serial GPIO")
Cc: Lars Povlsen <[e-mail]>
Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/pinctrl-microchip-sgpio.c

···
 	i = 0;
 	device_for_each_child_node(dev, fwnode) {
 		ret = microchip_sgpio_register_bank(dev, priv, fwnode, i++);
-		if (ret)
+		if (ret) {
+			fwnode_handle_put(fwnode);
 			return ret;
+		}
 	}
 
 	if (priv->in.gpio.ngpio != priv->out.gpio.ngpio) {