Fix versioning logic in ctest to get the correct latest version.
Fix versioning logic in ctest to get the correct latest version.

Change-Id: I2721bcd2da38b764ebe21dfb8fe7a39dd947075c

BUG=8500
TEST=Ran it against all boards

Review URL: http://codereview.chromium.org/4235001

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