tests: properly remove paired veth
tests: properly remove paired veth

lebauce/skydive,safchain/skydive,skydive-project/skydive,lebauce/skydive,safchain/skydive,lebauce/skydive,lebauce/skydive,safchain/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,skydive-project/skydive,safchain/skydive,lebauce/skydive,skydive-project/skydive,safchain/skydive,lebauce/skydive,skydive-project/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,skydive-project/skydive,safchain/skydive