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.

Before merging `fix-log-stdarg` (a1a296f) in `development`, you should have reverted commit f88dff0 on `development` (because it is an alternative implementation)…