Merge branch 'ma/worktree-cleanups'

Code clean-up. * ma/worktree-cleanups: worktree: use skip_prefix to parse target worktree: rename copy-pasted variable worktree: update renamed variable in comment worktree: inline `worktree_ref()` into its only caller wt-status: introduce wt_status_state_free_buffers() wt-status: print to s->fp, not stdout wt-status: replace sha1 mentions with oid