drm/drv: Remove invalid assignments

it's not necessary to assign a value of 0 to ret here, because if
the previous functions were executed correctly, ret would be 0.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/1607653037-37785-1-git-send-email-tiantao6@hisilicon.com

drivers/gpu/drm/drm_drv.c

@@ -894,8 +894,6 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_modeset_register_all(dev);
 
-	ret = 0;
-
 	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
 		 driver->name, driver->major, driver->minor,
 		 driver->patchlevel, driver->date,