openrc: add warning about cgroup initd script

packages/sys-apps/openrc/openrc-0.35.2.exheres-0

@@ -153,5 +153,8 @@ pkg_postinst() {
     # update the dependency tree after touching all files #224171
     [[ "${ROOT}" = "/" ]] &&
         "${ROOT}usr/$(exhost --target)/libexec"/rc/bin/rc-depend -u
+
+    elog "Since openrc 0.35 openrc has a cgroup init.d script which"
+    elog "you'll have to add to your startup if you need cgroups."
 }