hwrng: use platform_{get,set}_drvdata()

Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.

Also, unnecessary dev_set_drvdata() is removed, because the driver core
clears the driver data to NULL after device_release or on probe failure.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 20b962e..f9beed5 100644
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -700,7 +700,7 @@
 	if (err)
 		goto out_free_units;
 
-	dev_set_drvdata(&op->dev, np);
+	platform_set_drvdata(op, np);
 
 	schedule_delayed_work(&np->work, 0);
 
@@ -721,7 +721,7 @@
 
 static int n2rng_remove(struct platform_device *op)
 {
-	struct n2rng *np = dev_get_drvdata(&op->dev);
+	struct n2rng *np = platform_get_drvdata(op);
 
 	np->flags |= N2RNG_FLAG_SHUTDOWN;
 
@@ -736,8 +736,6 @@
 
 	kfree(np);
 
-	dev_set_drvdata(&op->dev, NULL);
-
 	return 0;
 }