build_image: image_to_vm needs board arg
build_image: image_to_vm needs board arg

BUG=none
TEST=build_image + cut and paste image_to_vm in the output

Change-Id: I9def13a56d796c1f034c834a8429e909b45afa02

Review URL: http://codereview.chromium.org/3181038

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