[media] dvb_usb_v2: .read_mac_address() callback changes

Give DVB adapter as a parameter for callback. MAC address is
adapter property and it could be (at least in theory) there
is devices having multiple adapters and all has own MAC.

Also add error handling. If callback fails error is returned
which leads device unregister.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-usb/dvb_usb.h

@@ -181,7 +181,7 @@ struct dvb_usb_device_properties {
 
 	int (*power_ctrl)       (struct dvb_usb_device *, int);
 	int (*read_config) (struct dvb_usb_device *d);
-	int (*read_mac_address) (struct dvb_usb_device *, u8 []);
+	int (*read_mac_address) (struct dvb_usb_adapter *, u8 []);
 	int (*frontend_attach) (struct dvb_usb_adapter *);
 	int (*tuner_attach) (struct dvb_usb_adapter *);
 	int (*frontend_ctrl) (struct dvb_frontend *, int);

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

@@ -203,22 +203,21 @@ int dvb_usbv2_adapter_dvb_init(struct dvb_usb_adapter *adap)
 				ret);
 		goto err;
 	}
+
 	adap->dvb_adap.priv = adap;
 
 	if (adap->dev->props->read_mac_address) {
-		if (adap->dev->props->read_mac_address(adap->dev,
-				adap->dvb_adap.proposed_mac) == 0)
-			pr_info("%s: MAC address: %pM\n", KBUILD_MODNAME,
-					adap->dvb_adap.proposed_mac);
-		else
-			pr_err("%s: MAC address reading failed\n",
-					KBUILD_MODNAME);
-	}
+		ret = adap->dev->props->read_mac_address(adap,
+				adap->dvb_adap.proposed_mac);
+		if (ret < 0)
+			goto err_dmx;
 
+		pr_info("%s: MAC address: %pM\n", KBUILD_MODNAME,
+				adap->dvb_adap.proposed_mac);
+	}
 
 	adap->demux.dmx.capabilities = DMX_TS_FILTERING | DMX_SECTION_FILTERING;
 	adap->demux.priv             = adap;
-
 	adap->demux.filternum        = 0;
 	if (adap->demux.filternum < adap->max_feed_count)
 		adap->demux.filternum = adap->max_feed_count;