Code review comment for ~smoser/cloud-init:fix/brightbox-less-matchy

Just for reference, bug 1661693 has some real collected output that shows:

$ ( cd /sys/class/dmi/id && sudo grep -r . . ) 2>/dev/null
./product_serial:srv-fajvm.gb1.brightbox.com
./bios_vendor:Seabios
./product_version:RHEL 6.6.0 PC
./power/runtime_active_kids:0
./power/runtime_suspended_time:0
./power/runtime_enabled:disabled
./power/runtime_active_time:0
./power/control:auto
./power/async:disabled
./power/runtime_usage:0
./power/runtime_status:unsupported
./chassis_vendor:Red Hat
./modalias:dmi:bvnSeabios:bvr0.5.1:bd01/01/2007:svnRedHat:pnKVM:pvrRHEL6.6.0PC:cvnRedHat:ct1:cvr:
./product_uuid:D5BF3AE9-7D9C-2923-0B1E-B0ED967E7DF0
./bios_version:0.5.1
./sys_vendor:Red Hat
./chassis_type:1
./uevent:MODALIAS=dmi:bvnSeabios:bvr0.5.1:bd01/01/2007:svnRedHat:pnKVM:pvrRHEL6.6.0PC:cvnRedHat:ct1:cvr:
./product_name:KVM
./bios_date:01/01/2007