LockTest fix misleading variable name

The insertLockRow is used for various tests to insert locks. Not all
inserted locks will be stale.

Change-Id: I8d16e8f1d0367668df76a1a121391dfcdd1a49b4
diff --git a/src/test/java/com/googlesource/gerrit/plugins/spannerrefdb/LockTest.java b/src/test/java/com/googlesource/gerrit/plugins/spannerrefdb/LockTest.java
index fb1eec5..f9f691c 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/spannerrefdb/LockTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/spannerrefdb/LockTest.java
@@ -171,7 +171,7 @@
   }
 
   private void insertLockRow(Timestamp timestamp) {
-    Mutation staleLock =
+    Mutation insertLock =
         Mutation.newInsertBuilder("locks")
             .set("project")
             .to(PROJECT_NAME_KEY.get())
@@ -184,6 +184,6 @@
             .set("owner")
             .to("")
             .build();
-    dbClient.write(Collections.singletonList(staleLock));
+    dbClient.write(Collections.singletonList(insertLock));
   }
 }