Bluetooth: Fix Pair Device response parameters for pairing failure

It is possible that pairing fails after we've already received remote
identity information. One example of such a situation is when
re-encryption using the LTK fails. In this case the hci_conn object has
already been updated with the identity address but user space does not
yet know about it (since we didn't notify it of the new IRK yet).

To ensure user space doesn't get a Pair Device command response with an
unknown address always use the same address in the response as was used
for the original command.

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