MAPREDUCE-5950. incorrect description in distcp2 document (Akira AJISAKA via aw)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1617993 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5998. CompositeInputFormat javadoc is broken (Akira AJISAKA via aw)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1617997 13f79535-47bb-0310-9956-ffa450edef68