unixd_set_global_mutex_perms() -> ap_unixd_set_global_mutex_perms()

in mod_example_ipc.
Addition to change in r722399.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@730703 13f79535-47bb-0310-9956-ffa450edef68