* g10/gpg.h (tofu): Rename field batch_update_ref to
batch_updated_wanted.
* g10/tofu.c (struct tofu_dbs_s): Rename field batch_update to
in_batch_transaction.
(begin_transaction): Only end an extant batch transaction if we are
not in a normal transaction.  When ending a batch transaction, really
end it.  Update ctrl->tofu.batch_update_started when starting a batch
transaction.
(end_transaction): Only release a batch transaction if ONLY_BATCH is
true.  When releasing a batch transaction, assert that there is no
open normal transaction.  Only allow DBS to be NULL if ONLY_BATCH is
true.
(tofu_begin_batch_update): Don't update
ctrl->tofu.batch_update_started.
(opendbs): Call end_transaction unconditionally.