fix a race condition that can cause a null pointer dereference on dce_pfd deep in namecache
fix a race condition that can cause a null pointer dereference on dce_pfd deep in namecache

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable