Bluetooth: Remove link type check in hci_disconn_complete_evt()

We can safely remove the link type check from hci_disconn_complete_
evt() since this check in not required for mgmt_disconnect_failed()
and mgmt_device_disconnected() does it internally.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>