Remove inet_ntoa(); use inet_ntoa_r() instead

[vangyzen]

Summary

inet_ntoa() cannot be used safely in a multithreaded environment
because it uses a static local buffer. Instead, use inet_ntoa_r()
with a buffer on the caller's stack.

Remove inet_ntoa() from head (no MFC).

[vangyzen]

sys/netpfil/pf/pf_osfp.c

123 ↗

(On Diff #25248)

Note: This INET6 conditional existed before my changes, but opt_inet6.h was not included, so INET6 was never defined. Apparently, pf's OS fingerprinting hasn't worked with IPv6 for a decade.

[kp]

pf bits look good to me.