9pfs: local: Fix possible memory leak in local_link()

There is a possible memory leak while local_link return -1 without free
odirpath and oname.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Jaijun Chen <chenjiajun8@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

hw/9pfs/9p-local.c

@@ -947,7 +947,7 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
         local_is_mapped_file_metadata(ctx, name)) {
         errno = EINVAL;
-        return -1;
+        goto out;
     }
 
     odirfd = local_opendir_nofollow(ctx, odirpath);