media: af9005: uninitialized variable printked

If usb_bulk_msg() fails, actual_length can be uninitialized.

Reported-by:  <syzbot+9d42b7773d2fecd983ab@syzkaller.appspotmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>