rootwrap: Fix KillFilter matching
rootwrap: Fix KillFilter matching

The match() method in the KillFilter is a bit buggy. Since most/many
run through this logic in their way to being matched, it creates subtle
issues elsewhere, specifically during linux_net bridge creation.  This
fixes two issues.

1. userargs gets elements directly popped off of it.  If the KillFilter
does not match the command its checking, the later filter that does is missing
one argument.
2. Type error on pid when checking /proc, this was causing issues on instance
tear down / kill -HUP'ing dnsmasq.

Fixes bug 921784

Change-Id: I058ff2276e3154e8c1f6cc7077fa485db60e5827

n0ano/gantt,n0ano/gantt