Need to revert back to using hostnamectl

Jason mentioned we also switched the defaulting logic too so went ahead and fixed that.

https://github.com/openshift/openshift-ansible/pull/5340

*** Bug 1489959 has been marked as a duplicate of this bug. ***

Verified this bug with openshift-ansible-3.7.0-0.126.1.git.0.0bb5b0c.el7.noarch and PASS.


# cat /etc/redhat-release 
Red Hat Enterprise Linux Atomic Host release 7.4


TASK [Set hostname] ************************************************************
Thursday 14 September 2017  06:39:40 +0000 (0:00:00.643)       0:01:40.782 **** 
changed: [qe-yadu371-master-etcd-1.0914-dbn.qe.rhcloud.com] => {
    "changed": true, 
    "cmd": [
        "hostnamectl", 
        "set-hostname", 
        "qe-yadu371-master-etcd-1"
    ], 
    "delta": "0:00:00.045691", 
    "end": "2017-09-14 06:39:40.745620", 
    "rc": 0, 
    "start": "2017-09-14 06:39:40.699929"
}
changed: [qe-yadu371-node-registry-router-1.0914-dbn.qe.rhcloud.com] => {
    "changed": true, 
    "cmd": [
        "hostnamectl", 
        "set-hostname", 
        "qe-yadu371-node-registry-router-1"
    ], 
    "delta": "0:00:00.064406", 
    "end": "2017-09-14 06:39:40.773065", 
    "rc": 0, 
    "start": "2017-09-14 06:39:40.708659"
}