Fix compilation on FreeBSD and OSX

This started as work to fix the 'core show sysinfo'
CLI command but while working on it oej
pointed out that read_credentials did not compile neither.
So while being there, fix that as well.

Thanks for all the testing oej!

(closes issue #14129)
Reported by: ys
Tested by: oej, mvanbaak


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@168609 65c4cc65-6c06-0410-ace0-fbb531ad65f3