Revert "drm/radeon/kms: fix typo in r600 cs checker"

This reverts commit d33ef52d.

This change seems to expose a bug in the 3D driver tiggered by
certain apps, so revert it to keep userspace working.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>

Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>