Revision 1629854

In FSFS, always use the same function to read the 'current' file.

Apart from the consistency aspect, this no longer lets atoi() mask
'current' file corruptions.  Recovery must be adopted to this.

* subversion/libsvn_fs_fs/fs_fs.c
  (get_youngest): Change signature because we will need the format
                  info as well - not just a repo path.  Call the util
                  function to read and interpret the 'current' file.
  (with_some_lock_file,
   svn_fs_fs__open,
   svn_fs_fs__youngest_rev,
   svn_fs_fs__ensure_revision_exists): Update callers.

* subversion/libsvn_fs_fs/fs.c
  (fs_open_for_recovery): Make sure, a valid 'current' file is available
                          for repository recovery.