HookQueue: Rename constructor 'queue' argument to avoid confusion

The `queue` argument gets assigned to the `workQueue` member, but
there is also a `queue` member.

Rename the argument to `workQueue` to match the member that it gets
assigned to, and prevent possible confusion with the other.

Change-Id: I3fc278e096028f06f0f91b5551e6e435c66fff93
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
index be70d12..82b2151 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
@@ -30,8 +30,8 @@
   private WorkQueue.Executor queue;
 
   @Inject
-  HookQueue(WorkQueue queue) {
-    workQueue = queue;
+  HookQueue(WorkQueue workQueue) {
+    this.workQueue = workQueue;
   }
 
   void submit(Path hook, HookArgs args) {