Host field should show the physical hostname

[laszlocph]

Today it shows the pod name as host.

The FluentD daemonset (https://github.com/fluent/fluentd-kubernetes-daemonset) follows a better practice, it shows the physical name of the node the log is coming from.

I'm thinking that the physical name would be more helpful in a troubleshooting situation. Patterns pointing to node failure would be easier to identify. Plus showing the pod name is kinda redundant. It's showing up in other fields as well.