drm/amdgpu: drop redundant sched job cleanup when cs is aborted

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: drop redundant sched job cleanup when cs is aborted

Once command submission failed due to userptr invalidation in amdgpu_cs_submit, legacy code will perform cleanup of scheduler job. However, it's not needed at all, as former commit has integrated job cleanup stuff into amdgpu_job_free. Otherwise, because of double free, a NULL pointer dereference will occur in such scenario.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2457