Refs #6699.  Add check to code that shouldn't fail.  (Our code should call check() when we really think it shouldn't fail.)
Refs #6699.  Add check to code that shouldn't fail.  (Our code should call check() when we really think it shouldn't fail.)

dbpercona/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,kbauskar/Percona-TokuBackup,percona/Percona-TokuBackup,tplavcic/Percona-TokuBackup,guiquanz/Percona-TokuBackup,kbauskar/Percona-TokuBackup,percona/Percona-TokuBackup,dbpercona/Percona-TokuBackup,guiquanz/Percona-TokuBackup,percona/Percona-TokuBackup,kbauskar/Percona-TokuBackup,tplavcic/Percona-TokuBackup,tplavcic/Percona-TokuBackup,dbpercona/Percona-TokuBackup,percona/Percona-TokuBackup,dbpercona/Percona-TokuBackup,guiquanz/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,kbauskar/Percona-TokuBackup,guiquanz/Percona-TokuBackup,Jun-Yuan/Percona-TokuBackup,tplavcic/Percona-TokuBackup