[media] hackrf: fix possible null ptr on debug printing

drivers/media/usb/hackrf/hackrf.c:1533 hackrf_probe()
error: we previously assumed 'dev' could be null (see line 1366)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/hackrf/hackrf.c

@@ -1530,7 +1530,7 @@ static int hackrf_probe(struct usb_interface *intf,
 err_kfree:
 	kfree(dev);
 err:
-	dev_dbg(dev->dev, "failed=%d\n", ret);
+	dev_dbg(&intf->dev, "failed=%d\n", ret);
 	return ret;
 }