driver core: platform: Respect return code of platform_device_register_full()

The platform_device_register_full() might return an error pointer. If we
instantiate platform device which is optional we may simplify the routine at
removal stage by simply calling platform_device_unregister(). For now it
requires to check parameter for being an error pointer in each caller.

To make users' life easier, check for an error pointer inside driver core.
Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/platform.c

@@ -234,7 +234,7 @@ struct platform_object {
  */
 void platform_device_put(struct platform_device *pdev)
 {
-	if (pdev)
+	if (!IS_ERR_OR_NULL(pdev))
 		put_device(&pdev->dev);
 }
 EXPORT_SYMBOL_GPL(platform_device_put);
@@ -447,7 +447,7 @@ void platform_device_del(struct platform_device *pdev)
 {
 	int i;
 
-	if (pdev) {
+	if (!IS_ERR_OR_NULL(pdev)) {
 		device_remove_properties(&pdev->dev);
 		device_del(&pdev->dev);