vhost: fix virtqueue initialization

[ upstream commit 7804bbd ]

This patches fixes virtqueue initialization issue causing
segfault or file descriptor being closed unexpectedly.

The wrong index was passed to init_vring_queue() by
alloc_vring_queue() when a hole in the virtqueue array was
met.

Fixes: 8acd7c2 ("vhost: fix virtqueues metadata allocation")

Reported-by: Yu Jiang <yux.jiang@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Tested-by: Yu Jiang <yux.jiang@intel.com>

lib/librte_vhost/vhost.c

@@ -575,7 +575,7 @@ alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 		}
 
 		dev->virtqueue[i] = vq;
-		init_vring_queue(dev, vring_idx);
+		init_vring_queue(dev, i);
 		rte_spinlock_init(&vq->access_lock);
 		vq->avail_wrap_counter = 1;
 		vq->used_wrap_counter = 1;