Almost all of our stdio is actually OpenBSD, so although this isn't
really a core part of stdio (it doesn't touch struct FILE, for example)
it probably makes sense for it to come from the same upstream. My
actual motivation though is that it's the only FreeBSD file we have
compiler warnings from.
This patch moves us over to -Werror by default, with only the DNS code
having -Wno-error.
Change-Id: Id244a5b445cba41b0a1ca30298ca7b1ed177810c
6593597931