drm/amd/amdgpu: consider kernel job always not guilty

[Why]
Currently all timedout job will be considered to be guilty. In SRIOV
multi-vf use case, the vf flr happens first and then job time out is
found. There can be several jobs timeout during a very small time slice.
And if the innocent sdma job time out is found before the real bad
job, then the innocent sdma job will be set to guilty. This will lead
to a page fault after resubmitting job.

[How]
If the job is a kernel job, we will always consider it not guilty

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>