fix rebuilding the cache database on XFS
fix rebuilding the cache database on XFS

cvmfs-testing/cvmfs,trshaffer/cvmfs,cvmfs-testing/cvmfs,Gangbiao/cvmfs,alhowaidi/cvmfsNDN,DrDaveD/cvmfs,Moliholy/cvmfs,alhowaidi/cvmfsNDN,cvmfs/cvmfs,cvmfs-testing/cvmfs,Moliholy/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,reneme/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,Moliholy/cvmfs,Gangbiao/cvmfs,MicBrain/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,cvmfs-testing/cvmfs,Moliholy/cvmfs,MicBrain/cvmfs,alhowaidi/cvmfsNDN,alhowaidi/cvmfsNDN,trshaffer/cvmfs,reneme/cvmfs,cvmfs/cvmfs,reneme/cvmfs,trshaffer/cvmfs,reneme/cvmfs,djw8605/cvmfs,Moliholy/cvmfs,cvmfs/cvmfs,cvmfs-testing/cvmfs,cvmfs/cvmfs,MicBrain/cvmfs,djw8605/cvmfs,djw8605/cvmfs,MicBrain/cvmfs,Gangbiao/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,reneme/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,MicBrain/cvmfs,DrDaveD/cvmfs,alhowaidi/cvmfsNDN