Correct documentation of ref-update hook regarding output

The output of the hook is only returned when the update is rejected,
not regardless of the return code as stated in the doc.

Change-Id: I93483f44e31e7055c302c0758084de868d1c4f93

src/main/resources/Documentation/hooks.md

diff --git a/src/main/resources/Documentation/hooks.md b/src/main/resources/Documentation/hooks.md
index b7e092c..c4b5fd7 100644
--- a/src/main/resources/Documentation/hooks.md
+++ b/src/main/resources/Documentation/hooks.md
@@ -15,8 +15,8 @@
 ref deletion) is received by Gerrit. It allows a request to be rejected before it
 is committed to the Gerrit repository.
 
-If the hook exits with non-zero return code the update will be rejected. Any output
-from the hook will be returned to the user, regardless of the return code.
+If the hook exits with non-zero return code the update will be rejected and any
+output will be returned to the user.
 
 ```
   ref-update --project <project name> --refname <refname> --uploader <uploader> --uploader-username <username> --oldrev <sha1> --newrev <sha1>