MAPREDUCE-4972. Coverage fixing for org.apache.hadoop.mapreduce.jobhistory (Aleksey Gorshkov via bobby)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1458917 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-0.23' into branch-0.23-gd