Merge branch 'jk/commit-graph-cleanup' into next

A pair of small fixups to "git commit-graph" have been applied.

* jk/commit-graph-cleanup:
  commit-graph: turn off save_commit_buffer
  commit-graph: don't show progress percentages while expanding reachable commits

diff --cc builtin/commit-graph.c
Simple merge

diff --cc commit-graph.c
Simple merge