pc8736x_gpio: use platform_device_unregister in pc8736x_gpio_cleanup()

platform_device_unregister() only calls platform_device_del() and
platform_device_put(), thus use platform_device_unregister() to
simplify the code.

Also the documents in platform.c shows that platform_device_del
and platform_device_put must _only_ be externally called in error
cases.  All other usage is a bug.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/char/pc8736x_gpio.c

@@ -345,8 +345,7 @@ static void __exit pc8736x_gpio_cleanup(void)
 	unregister_chrdev_region(MKDEV(major,0), PC8736X_GPIO_CT);
 	release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
 
-	platform_device_del(pdev);
-	platform_device_put(pdev);
+	platform_device_unregister(pdev);
 }
 
 module_init(pc8736x_gpio_init);