Use C++ thread_local rather than libcutils.

Test: treehugger
Change-Id: I11114b8e591e7ec034bac6420b1a0adda88e8af2
diff --git a/libs/binder/BufferedTextOutput.h b/libs/binder/BufferedTextOutput.h
index 1b27bb2..fdd532a 100644
--- a/libs/binder/BufferedTextOutput.h
+++ b/libs/binder/BufferedTextOutput.h
@@ -47,10 +47,7 @@
 private:
     struct BufferState;
     struct ThreadState;
-    
-    static  ThreadState*getThreadState();
-    static  void        threadDestructor(void *st);
-    
+
             BufferState*getBuffer() const;
             
     uint32_t            mFlags;