drm/i915: Remove 'retire' parameter from intel_fb_obj_flush

Setting retire=true is identical to using origin=ORIGIN_CS, so make the
same simplification to intel_fb_obj_flush() as already employed for
intel_fb_obj_invalidate().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170222114049.28456-6-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2806d6b..33bde17 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14285,7 +14285,7 @@ static int intel_user_framebuffer_dirty(struct drm_framebuffer *fb,
 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
 
 	i915_gem_object_flush_if_display(obj);
-	intel_fb_obj_flush(obj, false, ORIGIN_DIRTYFB);
+	intel_fb_obj_flush(obj, ORIGIN_DIRTYFB);
 
 	return 0;
 }