Have upload_prebuilts respect the debug flag.
Have upload_prebuilts respect the debug flag.

Chrome PFQ right now is uploading prebuilts which wasn't meant to happen :(

Change-Id: I502a0621a6c9f655e5a3f890dd79e00652925902

BUG=chromium-os:8693
TEST=Ran cbuildbot with --debug

Review URL: http://codereview.chromium.org/5595004

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