vm_image_util: use only ttyS0 for the console on GCE instances
vm_image_util: use only ttyS0 for the console on GCE instances

gtank/scripts,coreos/scripts,endocode/scripts,andrejro/coreos--scripts,andrejro/coreos--scripts,zhang0137/scripts,vmware/coreos-scripts,glevand/coreos--scripts,smilart/scripts,fivethreeo/scripts,mischief/scripts,BugRoger/scripts,smilart/scripts,zhang0137/scripts,mjg59/scripts,marineam/coreos-scripts,gtank/scripts,marineam/coreos-scripts,sigma/coreos-scripts,mischief/scripts,glevand/coreos--scripts,mischief/scripts,BugRoger/scripts,nicescale/scripts,mjg59/scripts,coreos/scripts,nicescale/scripts,trnubo/scripts,trnubo/scripts,sigma/coreos-scripts,BugRoger/scripts,fivethreeo/scripts,vmware/coreos-scripts,zhang0137/scripts,trnubo/scripts,vmware/coreos-scripts,gtank/scripts,mjg59/scripts,smilart/scripts,fivethreeo/scripts,andrejro/coreos--scripts,endocode/scripts,sigma/coreos-scripts,nicescale/scripts,endocode/scripts,marineam/coreos-scripts