[Spark-4432]close InStream after the block is accessed

InStream is not closed after data is read from Tachyon. which makes the blocks in Tachyon locked after accessed.

Author: Mingfei <mingfei.shi@intel.com>

Closes #3290 from shimingfei/lockFix and squashes the following commits:

fffe345 [Mingfei] close InStream after the block is accessed