virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0

We simplified virtqueue_add_buf(), make it clear in the callers.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index e626fa5..a11028a 100644 (file)
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -164,7 +164,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
                                r = virtqueue_add_buf(vq->vq, &sl, 1, 0,
                                                      dev->buf + started,
                                                      GFP_ATOMIC);
-                               if (likely(r >= 0)) {
+                               if (likely(r == 0)) {
                                        ++started;
                                        virtqueue_kick(vq->vq);
                                }
@@ -177,7 +177,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
                                r = 0;
                        }
 
-               } while (r >= 0);
+               } while (r == 0);
                if (completed == completed_before)
                        ++spurious;
                assert(completed <= bufs);