THRIFT-2609 TFileTransport.h unused field warning (clang 3.4)

Patch: Konrad Grochowski
diff --git a/lib/cpp/src/thrift/transport/TFileTransport.cpp b/lib/cpp/src/thrift/transport/TFileTransport.cpp
index c267f2e..625c877 100644
--- a/lib/cpp/src/thrift/transport/TFileTransport.cpp
+++ b/lib/cpp/src/thrift/transport/TFileTransport.cpp
@@ -751,7 +751,7 @@
       // if tailing the file, wait until there is enough data to start
       // the next chunk
       while(curChunk == (getNumChunks() - 1)) {
-        THRIFT_SLEEP_USEC(DEFAULT_CORRUPTED_SLEEP_TIME_US);
+        THRIFT_SLEEP_USEC(corruptedEventSleepTime_);
       }
       seekToChunk(curChunk + 1);
     } else {