ppdev: ppdev_init: do not return zero in case of failure

Error handling of parport_register_driver() in ppdev_init()
is broken because it deallocates all resources but still
returns zero.

Currently parport_register_driver() always succeeds.
Nevertheless it is worth to fix the issue.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/char/ppdev.c

@@ -783,7 +783,8 @@ static int __init ppdev_init (void)
 		err = PTR_ERR(ppdev_class);
 		goto out_chrdev;
 	}
-	if (parport_register_driver(&pp_driver)) {
+	err = parport_register_driver(&pp_driver);
+	if (err < 0) {
 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
 		goto out_class;
 	}