create error log file /tmp/q8reducerErr.log lazy only in error case
create error log file /tmp/q8reducerErr.log lazy only in error case

philjjoon/Big-Data-Benchmark-for-Big-Bench,philjjoon/Big-Data-Benchmark-for-Big-Bench,XiaominZhang/Big-Data-Benchmark-for-Big-Bench,XiaominZhang/Big-Data-Benchmark-for-Big-Bench,intel-hadoop/Big-Data-Benchmark-for-Big-Bench,intel-hadoop/Big-Data-Benchmark-for-Big-Bench