Bluetooth: Fix SMP confirmation callback handling

In the case that a local pairing confirmation (JUST_CFM) has been
selected as the method we need to use the user confirm request mgmt
event for it with the confirm_hint set to 1 (to indicate confirmation
without any specific passkey value). Without this (if passkey_notify was
used) the pairing would never proceed. This patch adds the necessary
call to mgmt_user_confirm_request in this scenario.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>