libcontainer: configs: extend unsupported os

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
diff --git a/libcontainer/configs/namespaces_windows.go b/libcontainer/configs/namespaces_unsupported.go
similarity index 85%
rename from libcontainer/configs/namespaces_windows.go
rename to libcontainer/configs/namespaces_unsupported.go
index f8fe47a..9a74033 100644
--- a/libcontainer/configs/namespaces_windows.go
+++ b/libcontainer/configs/namespaces_unsupported.go
@@ -1,3 +1,5 @@
+// +build !linux,!freebsd
+
 package configs
 
 // Namespace defines configuration for each namespace.  It specifies an