[media] dvb-bt8xx: handle errors from dvb_net_init

Clean up and error out if dvb_net_init fails (for example when
running out of memory).

From an audit of dvb_net_init callers, now that dvb_net_init
has learned to return a nonzero value from time to time.

[mchehab.redhat.com: codingstyle fix: printk() should include KERN_ facility level]
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/bt8xx/dvb-bt8xx.c

@@ -782,14 +782,21 @@ static int __devinit dvb_bt8xx_load_card(struct dvb_bt8xx_card *card, u32 type)
 		goto err_remove_mem_frontend;
 	}
 
-	dvb_net_init(&card->dvb_adapter, &card->dvbnet, &card->demux.dmx);
+	result = dvb_net_init(&card->dvb_adapter, &card->dvbnet, &card->demux.dmx);
+	if (result < 0) {
+		printk(KERN_ERR,
+		       "dvb_bt8xx: dvb_net_init failed (errno = %d)\n", result);
+		goto err_disconnect_frontend;
+	}
 
 	tasklet_init(&card->bt->tasklet, dvb_bt8xx_task, (unsigned long) card);
 
 	frontend_init(card, type);
 
 	return 0;
 
+err_disconnect_frontend:
+	card->demux.dmx.disconnect_frontend(&card->demux.dmx);
 err_remove_mem_frontend:
 	card->demux.dmx.remove_frontend(&card->demux.dmx, &card->fe_mem);
 err_remove_hw_frontend: