fix: use vm name to get vmi

[FrankYang0529]

harvester/harvester#4947

Test steps

1. Follow https://docs.harvesterhci.io/v1.2/rancher/cloud-provider#deploying-to-the-k3s-cluster-with-harvester-node-driver-experimental to create a RKE2 cluster.
   1-1. For Helm chart, use version v0.2.4.
   1-2. Set hostname in the cloud-config.
2. After cluster is up, it can't finish. Use the image from current branch to replace kube-system/harvester-cloud-provider. You may need to delete old harvester-cloud-provider pod manually, because it has anti-affinity.
3. The cluster should be up.

[starbops]

LGTM, thanks!