Backport r741871 from trunk:

    Use macro for determinig function name

This fixes an undefined reference to apr_proc_mutex_set_perms()
and  makes 1.6.x actually build.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/branches/1.6.x@1594696 13f79535-47bb-0310-9956-ffa450edef68