kubevirt-csi node: temp NFS mount dir removal error is ignored #4466

The kubevirt-csi node service ignores the error from removing its temporary NFS mount directory. NodePublishVolume in packages/apps/kubernetes/images/kubevirt-csi-driver/node.go creates the directory with os.MkdirTemp, mounts the NFS root there, and cleans up with defer os.Remove(tmpMount). golangci-lint flags that line (errcheck).

The deferred unmount runs first. If it fails, the unmount error is logged, but os.Remove then fails on a busy mount point and nothing reports it, so the directory stays behind in the node's temp dir. Checking the error and logging it would be enough. The repo runs no lint gate, so nothing catches this today.