[cli] fix args length checking in `dataset securitypolicy` (#6548)
[cli] fix args length checking in `dataset securitypolicy` (#6548)


srickardti/openthread,openthread/openthread,jwhui/openthread,openthread/openthread,jwhui/openthread,jwhui/openthread,openthread/openthread,abtink/openthread,srickardti/openthread,srickardti/openthread,abtink/openthread,jwhui/openthread,srickardti/openthread,abtink/openthread,abtink/openthread,openthread/openthread