drm/i915: Initialize ring->hangcheck upon ring init

When we reset and restart a ring, we also want to clear any existing
hangcheck.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -453,6 +453,8 @@ static int init_ring_common(struct intel_ring_buffer *ring)
 		ring->last_retired_head = -1;
 	}
 
+	memset(&ring->hangcheck, 0, sizeof(ring->hangcheck));
+
 out:
 	if (HAS_FORCE_WAKE(dev))
 		gen6_gt_force_wake_put(dev_priv);