media: dvbdev: fix error logic at dvb_register_device()

As reported by smatch:

	drivers/media/dvb-core/dvbdev.c: drivers/media/dvb-core/dvbdev.c:510 dvb_register_device() warn: '&dvbdev->list_head' not removed from list
	drivers/media/dvb-core/dvbdev.c: drivers/media/dvb-core/dvbdev.c:530 dvb_register_device() warn: '&dvbdev->list_head' not removed from list
	drivers/media/dvb-core/dvbdev.c: drivers/media/dvb-core/dvbdev.c:545 dvb_register_device() warn: '&dvbdev->list_head' not removed from list

The error logic inside dvb_register_device() doesn't remove
devices from the dvb_adapter_list in case of errors.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/dvb-core/dvbdev.c

@@ -506,6 +506,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 			break;
 
 	if (minor == MAX_DVB_MINORS) {
+		list_del (&dvbdev->list_head);
 		kfree(dvbdevfops);
 		kfree(dvbdev);
 		up_write(&minor_rwsem);
@@ -526,6 +527,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 		      __func__);
 
 		dvb_media_device_free(dvbdev);
+		list_del (&dvbdev->list_head);
 		kfree(dvbdevfops);
 		kfree(dvbdev);
 		mutex_unlock(&dvbdev_register_lock);
@@ -541,6 +543,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 		pr_err("%s: failed to create device dvb%d.%s%d (%ld)\n",
 		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 		dvb_media_device_free(dvbdev);
+		list_del (&dvbdev->list_head);
 		kfree(dvbdevfops);
 		kfree(dvbdev);
 		return PTR_ERR(clsdev);