We only suppress the error state from the context, iff we trigger the
GPU reset by hangcheck (igt_hang_ring). If we trigger an immediate reset
via igt_force_gpu_reset(), we will populate the error-state but not free
it because we thought we have it suppressed by the context parameter.
Always eat the error after we expect a GPU reset and have not specified
that we want to keep it.

The side-effect of keeping the error-state around after we deliberately
created it is that subsequent GPU hangs are not prominently recorded, as
the kernel believes they are secondary hangs (and we only announce the
first).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>