This will be used to indicate to the backend if a fetch is for
an AS REQ or TGS REQ. Samba needs to take some action in the
HDB_F_FOR_TGS_REQ case and always canonicalize the principal
names, even without HDB_F_CANON.
metze
Signed-off-by: Love Hörnquist Åstrand <lha@h5l.org>