mds: fix frag string rendering
mds: fix frag string rendering

Was mostly gibberish from df7c7bd79237d2a8b691f4e59433b0b39a9721a2

Signed-off-by: Sage Weil <c5b6ff1fd4f0bde10db63d7a3e07166cf6c4229f@dreamhost.com>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph