The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 
0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
 
 out_timer:
        del_timer_sync(&priv->timer);
 out_free:
-       platform_set_drvdata(pdev, NULL);
        kfree(priv);
        return err;
 }
        del_timer_sync(&priv->timer);
        iounmap(priv->io_base);
        release_mem_region(res->start, resource_size(res));
-       platform_set_drvdata(pdev, NULL);
        kfree(priv);
 
        return 0;