One fix for md in 4.0-rc4

Regression in recent patch causes crash on error path.
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Merge tag 'md/4.0-rc4-fix' of git://neil.brown.name/md

Pull bugfix for md from Neil Brown:
 "One fix for md in 4.0-rc4

  Regression in recent patch causes crash on error path"

* tag 'md/4.0-rc4-fix' of git://neil.brown.name/md:
  md: fix problems with freeing private data after ->run failure.

drivers/md/md.c

@@ -5080,7 +5080,8 @@ int md_run(struct mddev *mddev)
 	}
 	if (err) {
 		mddev_detach(mddev);
-		pers->free(mddev, mddev->private);
+		if (mddev->private)
+			pers->free(mddev, mddev->private);
 		module_put(pers->owner);
 		bitmap_destroy(mddev);
 		return err;

drivers/md/raid0.c

@@ -467,8 +467,6 @@ static int raid0_run(struct mddev *mddev)
 	dump_zones(mddev);
 
 	ret = md_integrity_register(mddev);
-	if (ret)
-		raid0_free(mddev, conf);
 
 	return ret;
 }