rfkill: gpio: fix memory leak in probe error path

Make sure to free the rfkill device in case registration fails during
probe.

Fixes: 5e7ca3937fbe ("net: rfkill: gpio: convert to resource managed allocation")
Cc: stable <stable@vger.kernel.org>	# 3.13
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/rfkill/rfkill-gpio.c

@@ -137,13 +137,18 @@ static int rfkill_gpio_probe(struct platform_device *pdev)
 
 	ret = rfkill_register(rfkill->rfkill_dev);
 	if (ret < 0)
-		return ret;
+		goto err_destroy;
 
 	platform_set_drvdata(pdev, rfkill);
 
 	dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
 
 	return 0;
+
+err_destroy:
+	rfkill_destroy(rfkill->rfkill_dev);
+
+	return ret;
 }
 
 static int rfkill_gpio_remove(struct platform_device *pdev)