macvtap: advance iov iterator when needed in macvtap_put_user()

When mergeable buffer is used, vnet_hdr_sz is greater than sizeof struct
virtio_net_hdr. So we need advance the iov iterators in this case.

Fixes 6c36d2e26cda1ad3e2c4b90dd843825fc62fe5b4 ("macvtap: Use iovec iterators")
Cc: Herbert Xu <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Acked-by: Herbert Xu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
1 file changed