[Bluetooth] Handle return values from driver core functions

Some return values of the driver core register and create functions
are not handled and so might cause unexpected problems.

Signed-off-by: Marcel Holtmann <[e-mail]>

net/bluetooth/hci_sysfs.c

···
 	struct hci_conn *conn = data;
 	int i;
 
-	device_register(&conn->dev);
+	if (device_register(&conn->dev) < 0) {
+		BT_ERR("Failed to register connection device");
+		return;
+	}
 
 	for (i = 0; conn_attrs[i]; i++)
-		device_create_file(&conn->dev, conn_attrs[i]);
+		if (device_create_file(&conn->dev, conn_attrs[i]) < 0)
+			BT_ERR("Failed to create connection attribute");
 }
 
 void hci_conn_add_sysfs(struct hci_conn *conn)
···
 		return err;
 
 	for (i = 0; bt_attrs[i]; i++)
-		device_create_file(dev, bt_attrs[i]);
+		if (device_create_file(dev, bt_attrs[i]) < 0)
+			BT_ERR("Failed to create device attribute");
 
 	return 0;
 }

net/bluetooth/l2cap.c

···
 		goto error;
 	}
 
-	class_create_file(bt_class, &class_attr_l2cap);
+	if (class_create_file(bt_class, &class_attr_l2cap) < 0)
+		BT_ERR("Failed to create L2CAP info file");
 
 	BT_INFO("L2CAP ver %s", VERSION);
 	BT_INFO("L2CAP socket layer initialized");

net/bluetooth/rfcomm/core.c

···
 
 	kernel_thread(rfcomm_run, NULL, CLONE_KERNEL);
 
-	class_create_file(bt_class, &class_attr_rfcomm_dlc);
+	if (class_create_file(bt_class, &class_attr_rfcomm_dlc) < 0)
+		BT_ERR("Failed to create RFCOMM info file");
 
 	rfcomm_init_sockets();
 

net/bluetooth/rfcomm/sock.c

···
 	if (err < 0)
 		goto error;
 
-	class_create_file(bt_class, &class_attr_rfcomm);
+	if (class_create_file(bt_class, &class_attr_rfcomm) < 0)
+		BT_ERR("Failed to create RFCOMM info file");
 
 	BT_INFO("RFCOMM socket layer initialized");
 

net/bluetooth/sco.c

···
 		goto error;
 	}
 
-	class_create_file(bt_class, &class_attr_sco);
+	if (class_create_file(bt_class, &class_attr_sco) < 0)
+		BT_ERR("Failed to create SCO info file");
 
 	BT_INFO("SCO (Voice Link) ver %s", VERSION);
 	BT_INFO("SCO socket layer initialized");