drm: drm_minor_register(): Clean up debugfs on failure

Call drm_debugfs_cleanup() in case drm_debugfs_init() fails to
cover for failure in the drm_driver.debugfs_init callback.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170126225621.12314-3-noralf@tronnes.org

drivers/gpu/drm/drm_drv.c

@@ -221,7 +221,7 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
 	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 	if (ret) {
 		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
-		return ret;
+		goto err_debugfs;
 	}
 
 	ret = device_add(minor->kdev);