Code clean-up.
* kn/reflog-migration-fix-followup:
reftable: prevent 'update_index' changes after adding records
refs: use 'uint64_t' for 'ref_update.index'
refs: mark `ref_transaction_update_reflog()` as static
These patches have been actually rebased onto a better base (the
`kn/reflog-migration` tip instead of the merge commit that merged this
tip).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>