Don't check aq64_minfree which is unsigned for negative values.

[jhb]

Summary

Don't check aq64_minfree which is unsigned for negative values.

This fixes a tautological comparison warning.

pjg@ moved this comparison down in an earlier revision, but that doesn't
fix the warning. The commit message from that revision mentioned keeping
the comparison for compat with other systems, but there was no reviewed
by, so it isn't clear if that was a hypothetical case or a real one.

Test Plan

• Compile tested.

[rwatson]

The comments could have to do with the au_qctrl structure, which uses "int", whereas the au_qctrl64 type uses "uint64_t". You can see the code handling the older structure a bit below this point, which likely has to do with compatibility with older Solaris/XNU versions rather than FreeBSD per se.

It should be OK to remove the check for the 64-bit version where the fields are 64-bit, although perhaps we should add a comment to make it obvious that this code is only robust if the fields are unsigned, which they are in OpenBSM.