Fix merge fail

Merge 4e3c93e failed: it should contain log.c from a1a296f, not a mix
between both varargs fix implementations (the other is f88dff0).

The resulting merge fails tests (on 64 bits architecture), while both
parents pass.
Merge pull request #64 from rom1v/mergefail

Fix merge fail, the faulty merge was produced with `git merge -Xtheirs` which did not give the intended effect.