Merge pull request #825 from stackhpc/docs-fix

Fix upgrading docs typo

Author: Alex-Welsh

doc/source/operations/upgrading.rst

@@ -438,7 +438,7 @@ Compare the old & new configuration:
 
 .. code-block:: console
 
-   diff -ru ~/kolla-diff-{old,new} > ~/kolla-diff.diff
+   diff -ru ~/kolla-diff/{old,new} > ~/kolla-diff.diff
    less ~/kolla-diff.diff
 
 Upgrading the Seed Hypervisor