Bluetooth: MGMT: Fix Add Device to responding before completing

Add Device with LE type requires updating resolving/accept list which
requires quite a number of commands to complete and each of them may
fail, so instead of pretending it would always work this checks the
return of hci_update_passive_scan_sync which indicates if everything
worked as intended.

Fixes: e8907f76 ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 3")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>