[media] dvb_usb_v2: probe/disconnect error handling

In my understanding we never call .disconnect() when .probe()
returns error. Change .probe() to return error all cases it cannot
handle given interface and simplify .disconnect() handling.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-usb/dvb_usb_init.c

@@ -393,7 +393,7 @@ int dvb_usbv2_probe(struct usb_interface *intf,
 
 	if (d->intf->cur_altsetting->desc.bInterfaceNumber !=
 			d->props.bInterfaceNumber) {
-		ret = 0;
+		ret = -ENODEV;
 		goto err_kfree;
 	}
 
@@ -419,7 +419,7 @@ EXPORT_SYMBOL(dvb_usbv2_probe);
 void dvb_usbv2_disconnect(struct usb_interface *intf)
 {
 	struct dvb_usb_device *d = usb_get_intfdata(intf);
-	const char *name = "generic DVB-USB module";
+	const char *name;
 
 	pr_debug("%s: pid=%d work_pid=%d\n", __func__, current->pid,
 			d->work_pid);
@@ -428,10 +428,8 @@ void dvb_usbv2_disconnect(struct usb_interface *intf)
 	if (d->work_pid != current->pid)
 		cancel_work_sync(&d->probe_work);
 
-	if (d) {
-		name = d->name;
-		dvb_usbv2_exit(d);
-	}
+	name = d->name;
+	dvb_usbv2_exit(d);
 
 	pr_info("%s: '%s' successfully deinitialized and disconnected\n",
 			KBUILD_MODNAME, name);