Ticket 47981 - COS cache doesn't properly mark vattr cache as
     invalid when there are multiple suffixes
    
    Bug Description:  When rebuilding the COS cache, we check each suffix for COS entries.
                      If the last suffix checked does not contain any COS entries, then the
                      virtual attribute cache is incorrectly not invalidated.  This allows
                      for already cached entries to hold onto the old COS attributes/values.
    
    Fix Description:  Only set the vattr_cacheable flag if a suffix contains COS entries, not
                      if it does not - by default the flag is not set.
    
    https://fedorahosted.org/389/ticket/47981
    
    Reviewed by: nhosoi(Thanks!)
    
    (cherry picked from commit 42e2df3858a4e14706d57b5c907d1d3768f4d970)