A bit of refactoring in FSFS, no functional change.
A bit of refactoring in FSFS, no functional change.

* subversion/libsvn_fs_fs/fs_fs.c
  (is_packed_rev): Abstract out a bit of magic for determining if a rev is
    packed or not.  This is a function and not a macro to make it easier
    to grow, should we need more complex logic later.
  (open_pack_or_rev_file, open_and_seek_revision, get_root_changes_offset,
   get_root_changes_offset, svn_fs_fs__set_revision_proplist): Use the
    new helper function.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@875057 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion