undefined local variable or method `paswd_lines'

The following typo fix should prevent the oo-accept-node command from failing.

```ruby
/usr/sbin/oo-accept-node:417:in `block in check_cgroup_procs': undefined local variable or method `paswd_lines' for main:Object (NameError)
	from /usr/sbin/oo-accept-node:411:in `each'
	from /usr/sbin/oo-accept-node:411:in `check_cgroup_procs'
	from /usr/sbin/oo-accept-node:829:in `<main>'
```