Rename fixup from TDelayedDestruction to DelayedDestruction.

Summary: [Folly] Rename fixup from TDelayedDestruction to DelayedDestruction.

Just affects comments.

Reviewed By: @haijunz

Differential Revision: D2373364

folly/io/async/AsyncSSLSocket.h

@@ -668,7 +668,7 @@ class AsyncSSLSocket : public virtual AsyncSocket {
    * Protected destructor.
    *
    * Users of AsyncSSLSocket must never delete it directly.  Instead, invoke
-   * destroy() instead.  (See the documentation in TDelayedDestruction.h for
+   * destroy() instead.  (See the documentation in DelayedDestruction.h for
    * more details.)
    */
   ~AsyncSSLSocket();

folly/io/async/test/MockAsyncServerSocket.h

@@ -29,7 +29,7 @@ public:
   typedef std::unique_ptr<MockAsyncServerSocket, Destructor> UniquePtr;
 
   // We explicitly do not mock destroy(), since the base class implementation
-  // in TDelayedDestruction is what actually deletes the object.
+  // in DelayedDestruction is what actually deletes the object.
   //MOCK_METHOD0(destroy,
   //             void());
   MOCK_METHOD1(bind,