The log_trees structs store the data that is used by client commits.
The primary struct is communicated over the wire so it includes the rid
and nr that identify the log. The _val struct was stored in btree item
values and was missing the rid and nr because those were stored in the
item's key.
It's madness to duplicate the entire struct just to shave off those two
fields. We can remove the _val struct and store the main struct in item
values, including the rid and nr.
Signed-off-by: Zach Brown <zab@versity.com>