Bluetooth: hci_event: Fix checking conn for le_conn_complete_evt
To prevent multiple conn complete events, we shouldn't look up the
conn with hci_lookup_le_connect, since it requires the state to be
BT_CONNECT. By the time the duplicate event is processed, the state
might have changed, so we end up processing the new event anyway.
Change the lookup function to hci_conn_hash_lookup_ba.