utils: Add missing symbols for FreeBSD

[NO NEW TESTS NEEDED]

Signed-off-by: Doug Rabson <dfr@rabson.org>

utils/utils_freebsd.go

@@ -0,0 +1,22 @@
+//go:build freebsd
+// +build freebsd
+
+package utils
+
+import "errors"
+
+func RunUnderSystemdScope(pid int, slice string, unitName string) error {
+	return errors.New("not implemented for freebsd")
+}
+
+func MoveUnderCgroupSubtree(subtree string) error {
+	return errors.New("not implemented for freebsd")
+}
+
+func GetOwnCgroup() (string, error) {
+	return "", errors.New("not implemented for freebsd")
+}
+
+func GetCgroupProcess(pid int) (string, error) {
+	return "", errors.New("not implemented for freebsd")
+}