Merge branch 'kn/pack-write-with-reduced-globals'

Code clean-up. * kn/pack-write-with-reduced-globals: pack-write: pass hash_algo to internal functions pack-write: pass hash_algo to `write_rev_file()` pack-write: pass hash_algo to `write_idx_file()` pack-write: pass repository to `index_pack_lockfile()` pack-write: pass hash_algo to `fixup_pack_header_footer()`