qa/workunits/cephtool/test.sh: fix thrash (more)

If I have to touch this again I will remove it.  Ugh.  This time,

ubuntu@teuthology:/var/lib/teuthworker/archive/teuthology-2014-03-11_02:30:01-rados-firefly-distro-basic-plana/125922

hit NXIO a few lines down because one of the OSDs was still down.

Signed-off-by: Sage Weil <sage@inktank.com>