This fixes a syzbot failure since actlen could be uninitialized,
but it was still used.

Syzbot link:

https://syzkaller.appspot.com/bug?extid=6bf9606ee955b646c0e1

Reported-and-tested-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>