Build issue under FreeBSD 11-CURRENT [JIRA: RIAK-2294]

[dmilith]

Hello. I did two small patches that makes build possible under FBSD 11 with clang 3.7.0:

https://bitbucket.org/verknowsys/sofin-definitions/commits/4c1761f887efc4de1cc3b4359382b0447b65a704

With these two, build passes.

[hmmr]

Thanks for the patch. Can you open a PR in basho/eleveldb, against branch 2.1? cc @erikleitch.