Add missing -d parameter

Change-Id: Id6f2319c0ebb51506013fb67ebbb5b55a53e2d04
diff --git a/Documentation/note-db.txt b/Documentation/note-db.txt
index bc0a3cf..d902a1ce 100644
--- a/Documentation/note-db.txt
+++ b/Documentation/note-db.txt
@@ -95,7 +95,7 @@
 
 To run the offline migration, run the `migrate-to-note-db` program:
 ----
-  java -jar gerrit.war migrate-to-note-db /path/to/site
+  java -jar gerrit.war migrate-to-note-db -d /path/to/site
 ----
 
 Once started, it is safe to cancel and restart the migration process, or to
@@ -124,7 +124,7 @@
 To run the migration in trial mode, add `--trial` to `migrate-to-note-db` or
 `daemon`:
 ----
-  java -jar gerrit.war migrate-to-note-db --trial /path/to/site
+  java -jar gerrit.war migrate-to-note-db --trial -d /path/to/site
   # OR
   java -jar gerrit.war daemon -d /path/to/site --migrate-to-note-db --trial
 ----