Revert "MAPREDUCE-7388. Remove unused variable _eof in GzipCodec.cc (#4429)"

This reverts commit fac895828f714b5587b57900d588acac69880c1e.

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/native/src/codec/GzipCodec.cc

@@ -135,6 +135,7 @@ GzipDecompressStream::GzipDecompressStream(InputStream * stream, uint32_t buffer
   }
   zstream->next_in = NULL;
   zstream->avail_in = 0;
+  _eof = false;
 }
 
 GzipDecompressStream::~GzipDecompressStream() {
@@ -155,6 +156,7 @@ int32_t GzipDecompressStream::read(void * buff, uint32_t length) {
     if (zstream->avail_in == 0) {
       int32_t rd = _stream->read(_buffer, _capacity);
       if (rd <= 0) {
+        _eof = true;
         size_t wt = zstream->next_out - (Bytef*)buff;
         return wt > 0 ? wt : -1;
       } else {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/native/src/codec/GzipCodec.h

@@ -60,6 +60,7 @@ protected:
   char * _buffer;
   uint32_t _capacity;
   void * _zstream;
+  bool _eof;
 public:
   GzipDecompressStream(InputStream * stream, uint32_t bufferSizeHint);