Need to allow pbench-fio to match newer versions rather than exact

[frival]

Right now pbench-fio will only run if it detects fio version 3.21 is installed - any other version and pbench-fio exits with an error. However, the pbench-agent can coexist with more than one fixed major/minor version and we'll likely run into situations where newer major (and possibly minor) versions of RHEL ship a newer fio than the exact match. Most likely a simple >= rather than = test would be sufficient; hopefully there doesn't need to be a list of known-broken versions as that would be ... unfortunate.

[portante]

We could consider using rpmdev-vercmp from the rpmdevtools package. See https://stackoverflow.com/questions/2996279/how-does-yum-compare-versions.

This would allow us to modify agent/util-scripts/require-rpm to see if the required RPM is the same or older than the installed version. But, it would add a new dependency.

Seems like it would be worth it.

[portante]

See also https://utcc.utoronto.ca/~cks/space/blog/linux/RPMShellVersionComparison.