report.py: fix crash on get_sched_mode
Current shader-db master report.py reports this for non-intel drivers (e.g. lima):
Traceback (most recent call last):
File "./report.py", line 384, in <module>
main()
File "./report.py", line 243, in main
get_sched_mode(before[p], after[p]))
File "./report.py", line 114, in get_sched_mode
p = " (scheduled: " + b["scheduled"]
KeyError: 'scheduled'
Add a check so it avoids accessing the 'scheduled' key when it isn't valid.