drm: don't drop handle reference on unload

since the handle references are all tied to a file_priv, and when it disappears
all the handle refs go with it.

The fbcon ones we'd only notice on unload, but the nouveau notifier one
would would happen on reboot.

nouveau: Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
nouveau: Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
i915 unload: Reported-by: Keith Packard <keithp@keithp.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/intel_fb.c

@@ -238,8 +238,8 @@ int intel_fbdev_destroy(struct drm_device *dev,
 
 	drm_framebuffer_cleanup(&ifb->base);
 	if (ifb->obj) {
-		drm_gem_object_handle_unreference(ifb->obj);
 		drm_gem_object_unreference(ifb->obj);
+		ifb->obj = NULL;
 	}
 
 	return 0;

drivers/gpu/drm/nouveau/nouveau_fbcon.c

@@ -352,7 +352,6 @@ nouveau_fbcon_destroy(struct drm_device *dev, struct nouveau_fbdev *nfbdev)
 
 	if (nouveau_fb->nvbo) {
 		nouveau_bo_unmap(nouveau_fb->nvbo);
-		drm_gem_object_handle_unreference_unlocked(nouveau_fb->nvbo->gem);
 		drm_gem_object_unreference_unlocked(nouveau_fb->nvbo->gem);
 		nouveau_fb->nvbo = NULL;
 	}

drivers/gpu/drm/nouveau/nouveau_notifier.c

@@ -79,7 +79,6 @@ nouveau_notifier_takedown_channel(struct nouveau_channel *chan)
 	mutex_lock(&dev->struct_mutex);
 	nouveau_bo_unpin(chan->notifier_bo);
 	mutex_unlock(&dev->struct_mutex);
-	drm_gem_object_handle_unreference_unlocked(chan->notifier_bo->gem);
 	drm_gem_object_unreference_unlocked(chan->notifier_bo->gem);
 	drm_mm_takedown(&chan->notifier_heap);
 }

drivers/gpu/drm/radeon/radeon_fb.c

@@ -97,7 +97,6 @@ static void radeonfb_destroy_pinned_object(struct drm_gem_object *gobj)
 		radeon_bo_unpin(rbo);
 		radeon_bo_unreserve(rbo);
 	}
-	drm_gem_object_handle_unreference(gobj);
 	drm_gem_object_unreference_unlocked(gobj);
 }