Remove redundant sysctl() call in procapi for macos single-pid query #7851
Remove redundant sysctl() call in procapi for macos single-pid query #7851

(This was back-ported from #7708 in 8.9.8)
When calling sysctl() for a single pid, we know the size of the data
structure, so we don't need an extra call to find it out.

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor