kubectl-ko: fix subnet diagnose failure

[zhangzujian]

Pull Request

• Make sure you have followed Kube-OVN Code Style.

What type of this PR

Examples of user facing changes:

• Features
• Bug fixes
• Docs
• Tests

Which issue(s) this PR fixes

I0307 05:23:46.455574   11168 ping.go:157] start to check pod connectivity
I0307 05:23:46.460670   11168 ping.go:176] TCP connectivity to pod ovn-default-conn-check-server-5j8x8 10.16.0.13 failed
I0307 05:23:46.460827   11168 ping.go:183] UDP connectivity to pod ovn-default-conn-check-server-5j8x8 10.16.0.13 failed
I0307 05:23:46.696753   11168 ping.go:208] ping pod: ovn-default-conn-check-server-5j8x8 10.16.0.13, count: 3, loss count 0, average rtt 0.24ms
I0307 05:23:46.697330   11168 ping.go:176] TCP connectivity to pod ovn-default-conn-check-server-97sp6 10.16.0.12 failed
I0307 05:23:46.697408   11168 ping.go:183] UDP connectivity to pod ovn-default-conn-check-server-97sp6 10.16.0.12 failed
I0307 05:23:46.984569   11168 ping.go:208] ping pod: ovn-default-conn-check-server-97sp6 10.16.0.12, count: 3, loss count 0, average rtt 0.08ms