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: NEuler Robot <euler.robot@huawei.com>
Signed-off-by: NJaijun Chen <chenjiajun8@huawei.com>
Signed-off-by: NXiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: NChristian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: NGreg Kurz <groug@kaod.org>
(cherry picked from commit 841b8d09)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

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);