vhost: Remove the unused variable.

The patch (7235acdb1) changed the way of the work
flushing in which the queued seq, done seq, and the
flushing are not used anymore. Then remove them now.

Fixes: 7235acdb1 ("vhost: simplify work flushing")
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/vhost.c

@@ -181,7 +181,6 @@ void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn)
 {
 	clear_bit(VHOST_WORK_QUEUED, &work->flags);
 	work->fn = fn;
-	init_waitqueue_head(&work->done);
 }
 EXPORT_SYMBOL_GPL(vhost_work_init);
 

drivers/vhost/vhost.h

@@ -20,10 +20,6 @@ typedef void (*vhost_work_fn_t)(struct vhost_work *work);
 struct vhost_work {
 	struct llist_node	  node;
 	vhost_work_fn_t		  fn;
-	wait_queue_head_t	  done;
-	int			  flushing;
-	unsigned		  queue_seq;
-	unsigned		  done_seq;
 	unsigned long		  flags;
 };