6808625: Incomplete code sample in Deflater javadoc

Summary: added compresser.end() into example
Reviewed-by: martin

src/share/classes/java/util/zip/Deflater.java

@@ -49,6 +49,7 @@ package java.util.zip;
  *     compresser.setInput(input);
  *     compresser.finish();
  *     int compressedDataLength = compresser.deflate(output);
+ *     compresser.end();
  *
  *     // Decompress the bytes
  *     Inflater decompresser = new Inflater();