Attempt to fix bug 5684

Attempt to fix bug 5684

With the ctdb checkin dde9f3f006 tdb optimized out write lock checks for
write-enabled transaction. Sadly, this also removed the possibility to ever
remove dead records left over from tdb_delete calls within a transaction.

Tridge, please check this! Did dde9f3f006 have any reason beyond performance
optimizations?

Thanks,

Volker
(cherry picked from samba commit 3f884c4ae36f3260e63626bdd4989d9258ae6497)
(This used to be commit 1d85e0647e287d269b3f6b534da88f497d6f76c3)
(cherry picked from samba commit 8c88209c6f4b57b0dbe1459bd5bc583c5d321758)

Signed-off-by: Stefan Metzmacher <metze@samba.org>