net/virtio: fix repeated freeing of virtqueue

net/virtio: fix repeated freeing of virtqueue

When virtio_init_queue returns error, the memory of vq is freed.
But the value of hw->vqs[queue_idx] does not restore.
If virtio_init_queue returns error, the memory of vq is freed again
in virtio_free_queues.

Fixes: 69c80d4ef89b ("net/virtio: allocate queue at init stage")
Cc: stable@dpdk.org
Signed-off-by: Gaoxiang Liu <liugaoxiang@huawei.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>