The code was doing a runtime check, anyway.  The compile time check isn't
always valid (cross-compiling, packages).

Review: https://reviewboard.asterisk.org/r/2245/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@377977 65c4cc65-6c06-0410-ace0-fbb531ad65f3