If we somehow get disassociated while still waiting for a beacon
during connection, we can end up printing the

  No beacon heard and the session protection is over already...

message even if we aren't really quite waiting for it anymore.
Remove the time event, if it's running, when we get disassociated
and don't need to wait for beacons anymore.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211024181719.6192e2363784.Ie9c2bfdc30dcfff2c4dd7c393c79e3ac182840a9@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>