remove dracut-files.tbz2 [v2]
    
    Resolves: bz816864
    
    currently kexec-tools maintains kdump dracut modules as below dir hierarchy:
     [dave@localhost fedpkg]$ tree kexec-tools/kdump_dracut_modules
     kexec-tools/kdump_dracut_modules
     `-- 99kdumpbase
         |-- kdump.sh
         `-- module-setup.sh
    
    But in kexec-tools.spec, sources line is below:
    Source100: dracut-files.tbz2
    
    So we need to manually generate the dracut-files.tbz2, upload it, modify
    the sources file which contains the md5sum of these binaies, and then do
    the building. The more headache problem is this make local tests of
    changes to kdump module hard.
    
    To ease future work, move the files to TOPDIR, cp the sources instead.
    
    Thanks for help from dzickus
    [v1->v2]: Also remove dracut-files.tbz2 from sources file
              ChaoWang: add prefix to dracut files