[Stable-8.0.3 53/54] vdpa: fix not using CVQ buffer in case of error

[Michael Tokarev]

From: Eugenio Pérez <eperezma@redhat.com>

Bug introducing when refactoring.  Otherway, the guest never received
the used buffer.

Fixes: be4278b65fc1 ("vdpa: extract vhost_vdpa_net_cvq_add from 
vhost_vdpa_net_handle_ctrl_avail")
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20230602173451.1917999-1-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
(cherry picked from commit d45243bcfc61a3c34f96a4fc34bffcb9929daba0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 99904a0da7..1c3086c892 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -765,7 +765,7 @@ static int 
vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
     }
 
     if (*s->status != VIRTIO_NET_OK) {
-        return VIRTIO_NET_ERR;
+        goto out;
     }
 
     status = VIRTIO_NET_ERR;
-- 
2.39.2