I did the same, but git log visualize gave me two suspects at the end, the first being the same as yours:
$this->bbcode_second_pass_code('', 'commit 17010c230edf9933176948934276cf18007ccadb
Author: Tom Gundersen <teg@jklm.no>
Date: Tue Oct 6 16:31:58 2015 +0200
siphash24: coding-style fixes
Drop custom types. Drop unnecessary macros. Fix whitespace. Add asserts.
commit 0cb3c286883b694fc52a18a3b559ff98931641f3
Author: Tom Gundersen <teg@jklm.no>
Date: Tue Oct 6 15:04:42 2015 +0200
siphash24: unify API
Make the API of the new helpers more similar to the old wrapper.
In particular we now return the hash as a byte string to avoid
any endianness problems.
')
Link to the second commit:
https://github.com/systemd/systemd/commit/0cb3c28