Fix CGROUPS_ROOT_* tests on systemd platforms.
Tests do not run with systemd configured, so any dependency on systemd
will fail some checks.
This fixes the `LinuxLauncher` to use the correct systemd-guard function.
Review: https://reviews.apache.org/r/43432/
diff --git a/src/slave/containerizer/linux_launcher.cpp b/src/slave/containerizer/linux_launcher.cpp
index 16ca8f7..34d622a 100644
--- a/src/slave/containerizer/linux_launcher.cpp
+++ b/src/slave/containerizer/linux_launcher.cpp
@@ -113,7 +113,7 @@
return new LinuxLauncher(
flags,
freezerHierarchy.get(),
- systemd::exists() ?
+ systemd::enabled() ?
Some(systemd::hierarchy()) :
Option<std::string>::none());
}