pkg: Build pkg/util on FreeBSD

Remove freebsd from the unsupported list and add missing symbols.

[NO NEW TESTS NEEDED]

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

pkg/util/utils_freebsd.go

@@ -0,0 +1,12 @@
+//go:build freebsd
+// +build freebsd
+
+package util
+
+import (
+	"errors"
+)
+
+func GetContainerPidInformationDescriptors() ([]string, error) {
+	return []string{}, errors.New("this function is not supported on freebsd")
+}

pkg/util/utils_unsupported.go

@@ -1,5 +1,5 @@
-//go:build darwin || windows
+//go:build darwin || windows || freebsd
-// +build darwin windows
+// +build darwin windows freebsd
 
 package util