watchdog: intel-mid_wdt: Convert to use device managed functions

Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts used
to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Drop assignments to otherwise unused variables
- Drop remove function
- Drop platform_set_drvdata()
- Use devm_watchdog_register_driver() to register watchdog device
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/watchdog/intel-mid_wdt.c

@@ -137,7 +137,6 @@ static int mid_wdt_probe(struct platform_device *pdev)
 	wdt_dev->parent = &pdev->dev;
 
 	watchdog_set_drvdata(wdt_dev, &pdev->dev);
-	platform_set_drvdata(pdev, wdt_dev);
 
 	ret = devm_request_irq(&pdev->dev, pdata->irq, mid_wdt_irq,
 			       IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
@@ -151,7 +150,7 @@ static int mid_wdt_probe(struct platform_device *pdev)
 	/* Make sure the watchdog is not running */
 	wdt_stop(wdt_dev);
 
-	ret = watchdog_register_device(wdt_dev);
+	ret = devm_watchdog_register_device(&pdev->dev, wdt_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "error registering watchdog device\n");
 		return ret;
@@ -162,16 +161,8 @@ static int mid_wdt_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int mid_wdt_remove(struct platform_device *pdev)
-{
-	struct watchdog_device *wd = platform_get_drvdata(pdev);
-	watchdog_unregister_device(wd);
-	return 0;
-}
-
 static struct platform_driver mid_wdt_driver = {
 	.probe		= mid_wdt_probe,
-	.remove		= mid_wdt_remove,
 	.driver		= {
 		.name	= "intel_mid_wdt",
 	},