task #28910367
commit 14d46d7abc3973a47e8eb0eb5eb87ee8d910a505 upstream

virtio-fs will need to query the length of fuse_arg lists.  Make the
symbol visible.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NLiu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>