drm/i915/debug: Convert i915_verify_active() to scan all lists

... and check more regularly.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 5103b95..d89b887 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -579,6 +579,8 @@
 	int ret;
 
 	ring->dev = dev;
+	INIT_LIST_HEAD(&ring->active_list);
+	INIT_LIST_HEAD(&ring->request_list);
 
 	if (I915_NEED_GFX_HWS(dev)) {
 		ret = init_status_page(dev, ring);
@@ -627,8 +629,6 @@
 		if (ring->space < 0)
 			ring->space += ring->size;
 	}
-	INIT_LIST_HEAD(&ring->active_list);
-	INIT_LIST_HEAD(&ring->request_list);
 	return ret;
 
 err_unmap: