Fix printing of 64-bit counters in systat on 32-bit ppc

[tuexen]

Summary

Several statistic counters are uint64_t values and are printed by systat using %lu. This results in displaying wrong numbers. Use PRIu64 instead.

While there, print variables of size_t using %zd.

Test Plan

Run systat -ip, systat -tcp, and so on on various platforms including ppc32, ppc64, i386 and amd64.