drm/i915: move fence lru to struct drm_i915_fence_reg

This lru tracks fences, not objects, so move it to where it belongs.
As a side effect, this nicely shrinks drm_i915_gem_object by two
pointers.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 001e2f3..7f797ef 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -128,6 +128,7 @@
 
 struct drm_i915_fence_reg {
 	struct drm_gem_object *obj;
+	struct list_head lru_list;
 };
 
 struct sdvo_device_mapping {
@@ -665,9 +666,6 @@
 	/** This object's place on GPU write list */
 	struct list_head gpu_write_list;
 
-	/** This object's place on the fenced object LRU */
-	struct list_head fence_list;
-
 	/**
 	 * This is set if the object is on the active or flushing lists
 	 * (has pending rendering), and is not set if it's on inactive (ready