Revert "THRIFT-3225 Fix TPipeServer unpredictable behavior on close"

This reverts commit f48588f124fb8636f94bf23d098d4483f077e2de.
diff --git a/lib/cpp/src/thrift/transport/TPipeServer.cpp b/lib/cpp/src/thrift/transport/TPipeServer.cpp
index 44295f1..3779d7f 100644
--- a/lib/cpp/src/thrift/transport/TPipeServer.cpp
+++ b/lib/cpp/src/thrift/transport/TPipeServer.cpp
@@ -119,10 +119,7 @@
     }
   }
 
-  virtual void close() { 
-    TAutoCrit lock(pipe_protect_);
-    Pipe_.reset(); 
-  }
+  virtual void close() { Pipe_.reset(); }
 
   virtual boost::shared_ptr<TTransport> acceptImpl();