net/filter-rewriter.c: Fix rewirter checksum bug when use virtio-net

Because vnet_hdr have a offset to net packet, we must add it when use
virtio-net.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
1 file changed