Bluetooth: SMP: Fix trying to use non-existent local OOB data

A remote device may claim that it has received our OOB data, even
though we never geneated it. Add a new flag to track whether we
actually have OOB data, and ignore the remote peer's flag if haven't
generated OOB data.

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