setcifsacl: fix endianness on SIDs provided by winbind routines

setcifsacl: fix endianness on SIDs provided by winbind routines

Winbind keeps SID fields in host-endian format, but setcifsacl doesn't
currently account for that. Make sure that when we get a valid SID
from wbc that we convert the subauth fields to little-endian, which
the server will expect. The other fields are single bytes and don't
need conversion.

Signed-off-by: Jeff Layton <jlayton@samba.org>