Don't kill sdcards with boot_tries
Don't kill sdcards with boot_tries

USB/SDCard boot devices typicaly don't run software updater,
and won't have success ever set. We never want to try to
fall back to the empty B partition either. The workaround
for this is to set the successful bit regardless of actual
boot success.

bug=6395
Change-Id: I67c625804203b13be9a0c626c404fa38bafb5445

Review URL: http://codereview.chromium.org/3344008

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