Update doc/update/8.1-to-8.2.md

[ci skip]

doc/update/8.1-to-8.2.md

@@ -2,7 +2,8 @@
 
 **NOTE:** GitLab 8.0 introduced several significant changes related to
 installation and configuration which *are not duplicated here*. Be sure you're
-already running a working version of 8.0 before proceeding with this guide.
+already running a working version of at least 8.0 before proceeding with this
+guide.
 
 ### 0. Double-check your Git version
 
@@ -67,7 +68,7 @@ sudo -u git -H git checkout 8-2-stable-ee
 ```bash
 cd /home/git/gitlab-shell
 sudo -u git -H git fetch
-sudo -u git -H git checkout v2.6.5
+sudo -u git -H git checkout v2.6.6
 ```
 
 ### 5. Replace gitlab-git-http-server with gitlab-workhorse
@@ -80,7 +81,7 @@ from GitLab 8.1.
 cd /home/git
 sudo -u git -H git clone https://gitlab.com/gitlab-org/gitlab-workhorse.git
 cd gitlab-workhorse
-sudo -u git -H git checkout 0.3.1
+sudo -u git -H git checkout 0.4.1
 sudo -u git -H make
 ```
 
@@ -165,12 +166,12 @@ To make sure you didn't miss anything run a more thorough check:
 
 If all items are green, then congratulations, the upgrade is complete!
 
-## Things went south? Revert to previous version (8.0)
+## Things went south? Revert to previous version (8.1)
 
 ### 1. Revert the code to the previous version
 
-Follow the [upgrade guide from 7.14 to 8.0](7.14-to-8.0.md), except for the database migration
-(The backup is already migrated to the previous version)
+Follow the [upgrade guide from 8.0 to 8.1](8.0-to-8.1.md), except for the
+database migration (the backup is already migrated to the previous version).
 
 ### 2. Restore from the backup