fix typo in workunits example
fix typo in workunits example

SUSE/teuthology,robbat2/teuthology,yghannam/teuthology,tchaikov/teuthology,ivotron/teuthology,tchaikov/teuthology,SUSE/teuthology,dreamhost/teuthology,ivotron/teuthology,ceph/teuthology,michaelsevilla/teuthology,t-miyamae/teuthology,caibo2014/teuthology,SUSE/teuthology,ktdreyer/teuthology,dreamhost/teuthology,caibo2014/teuthology,t-miyamae/teuthology,dmick/teuthology,michaelsevilla/teuthology,zhouyuan/teuthology,robbat2/teuthology,dmick/teuthology,dmick/teuthology,ktdreyer/teuthology,ceph/teuthology,zhouyuan/teuthology,yghannam/teuthology