issue 753838  - A bad CL caused provision failures on slaves, and the failures were treated as lab_only_failure and so no CLs were rejected. CQ kept picking up all CLs including the bad CL to retry and the CQ kept failing. Probably need a better mechanism to distinguish provision failures from other lab failures, so the master can kick out potential bad CLs. 

jrbarnette@ suggested the run_suite job can return a different code for provision failures.

http://shortn/_b6Z7iLgSmd