mm: memfd_luo: restore and free memfd_luo_ser on failure

memfd_luo_ser has the serialization metadata. It is of no use once
restoration fails. Free it on failure.

Link: https://lkml.kernel.org/r/[e-mail]
Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd")
Signed-off-by: Pratyush Yadav (Google) <[e-mail]>
Reviewed-by: Mike Rapoport (Microsoft) <[e-mail]>
Reviewed-by: Pasha Tatashin <[e-mail]>
Cc: Baolin Wang <[e-mail]>
Cc: Hugh Dickins <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/memfd_luo.c

···
 	file = memfd_alloc_file("", 0);
 	if (IS_ERR(file)) {
 		pr_err("failed to setup file: %pe\n", file);
-		return PTR_ERR(file);
+		err = PTR_ERR(file);
+		goto free_ser;
 	}
 
 	vfs_setpos(file, ser->pos, MAX_LFS_FILESIZE);
···
 
 put_file:
 	fput(file);
-
+free_ser:
+	kho_restore_free(ser);
 	return err;
 }