Bluetooth: mgmt: Fix return value for set_class

The return parameters for Set Device Class should consist of the new
class value.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/mgmt.c

@@ -1470,7 +1470,7 @@ static int set_dev_class(struct sock *sk, u16 index, void *data, u16 len)
 
 	if (err == 0)
 		err = cmd_complete(sk, index, MGMT_OP_SET_DEV_CLASS, 0,
-								NULL, 0);
+							hdev->dev_class, 3);
 
 unlock:
 	hci_dev_unlock(hdev);