log nodename rebooting

[philips]

Currently the logs don't help in debugging with the name of a node that is rebooting.

I0504 01:49:36.708757       1 operator.go:243] Found 1 (of max 1) rebooting nodes; waiting for completion
I0504 01:49:41.680873       1 operator.go:221] Found 1 rebooted nodes, setting annotation "container-linux-update.v1.coreos.com/reboot-ok" to false

[dghubble]

Agreed, this is important for usability, I'll relax the logging to include that