ipa-kdb: fix compiler warnings
    
    There are few fields in KDB structures that have 'conflicting' types but
    need to be compared. They come from MIT Kerberos and we have no choice
    here.
    
    In the same way, SID structures have own requirements.
    
    Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Robbie Harwood <rharwood@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>