nuke: reboot if rbd is mounted
nuke: reboot if rbd is mounted

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