fix crash when canceling a non-scheduled job
fix crash when canceling a non-scheduled job

In such case, actual_device is still None. Moreover we should jump directly
from submitted to finished.

Change-Id: I888b3c2d8440308c2b3365dbbcf52b6b70ce9384

Linaro/lava-server,Linaro/lava-server,Linaro/lava-server,Linaro/lava-server