Code review comment for ~pkopylov/qa-regression-testing:fix-test-util-linux-swapon

Hay Pavel, thanks for submitting this. One issue with converting to swapon --show is that the Ubuntu Security Team is still supporting 14.04 LTS / trusty, where the swapon command does not support the --show argument.

I have pushed a commit that will use swapon --show in newer releases, and also checks the contents of /proc/swaps, and doesn't expect any output from swapon if there's no entries besides the column headers in /proc/swaps. Probably the better solution is to always create a small swapfile and check the output of swapon to ensure it's present.

The commit is at https://git.launchpad.net/qa-regression-testing/commit/?id=079add3ae1812d37164c80cf06ff6d399a8b27c3

Thanks!