weaved: DISALLOW_COPY_AND_ASSIGN should be private

Change-Id: Ibea4ea8bcfa36a1cfe98188407805346dca22e84
Signed-off-by: Bin Chen <pierr.chen@gmail.com>
diff --git a/buffet/mdns_client.h b/buffet/mdns_client.h
index 0a7690a..2465198 100644
--- a/buffet/mdns_client.h
+++ b/buffet/mdns_client.h
@@ -42,7 +42,7 @@
 
   static std::unique_ptr<MdnsClient> CreateInstance();
 
- protected:
+ private:
   DISALLOW_COPY_AND_ASSIGN(MdnsClient);
 };