Bluetooth: Fix updating conn->auth_type in hci_io_capa_request_evt

In some circumstances hci_get_auth_req will return a value different
from the current conn->auth_type. In these cases update conn->auth_type
so that when a user confirm request comes it doesn't falsely trigger
auto-accept.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>