Staging: ipack/devices/ipoctal: avoid kernel oops when uninstalling

When uninstalling a device, there is a loop of calls that produces, at the end,
two calls to __ipoctal_remove() function with the same ipack_device argument.

The first time works fine, but the second will fail in tty_unregister_driver()

To avoid this situation, the call to __ipoctal_remove() it is done only from the
ipack bus driver and not from the ipack device driver.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ipack/devices/ipoctal.c

@@ -853,11 +853,6 @@ static void __ipoctal_remove(struct ipoctal *ipoctal)
 
 	tty_unregister_driver(ipoctal->tty_drv);
 	put_tty_driver(ipoctal->tty_drv);
-
-	/* Tell the carrier board to free all the resources for this device */
-	if (ipoctal->dev->bus->ops->remove_device != NULL)
-		ipoctal->dev->bus->ops->remove_device(ipoctal->dev);
-
 	list_del(&ipoctal->list);
 	kfree(ipoctal);
 }
@@ -889,7 +884,7 @@ static void __exit ipoctal_exit(void)
 	struct ipoctal *p, *next;
 
 	list_for_each_entry_safe(p, next, &ipoctal_list, list)
-		__ipoctal_remove(p);
+		p->dev->bus->ops->remove_device(p->dev);
 
 	ipack_driver_unregister(&driver);
 }