[SPARK-4901] [SQL] Hot fix for ByteWritables.copyBytes

HiveInspectors.scala failed in compiling with Hadoop 1, as the BytesWritable.copyBytes is not available in Hadoop 1.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3742 from chenghao-intel/settable_oi_hotfix and squashes the following commits:

bb04d1f [Cheng Hao] hot fix for ByteWritables.copyBytes