On the fsfs-format7 branch: remove an used variable.
No functional change.

* subversion/libsvn_fs_fs/fs_fs.c
  (svn_fs_fs__write_format): drop unused variable

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1489814 13f79535-47bb-0310-9956-ffa450edef68