Change ipsec_address() and ipsec_logsastr() functions to take two additional arguments - buffer and size of this buffer.

[ae]

Summary

ipsec_address() is used to convert sockaddr structure to presentation
format. The IPv6 part of this function returns pointer to the on-stack
buffer and at the moment when it will be used by caller, it becames
invalid. IPv4 version uses 4 static buffers and returns pointer to
new buffer each time when it called. But anyway it is still possible
to get corrupted data when several threads will use this function.
  https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=185996

ipsec_logsastr() is used to format string describing SA entry. It also
uses static buffer and has the same problem with concurrent threads.

To fix these problems I added the buffer pointer and size of this
buffer to arguments. Now each caller will pass buffer and its size
to these functions. Also, I converted all places where these functions
are used (except disabled code).

And now ipsec_address() uses inet_ntop() function from libkern.

Test Plan

Without patch and sysctl net.inet.ipsec.debug=1 we have such messages for IPv6 packets:

ipsec_common_input: no key association found for SA 0T\^S\^Z\^A����_/00005fb7/50
ipsec_common_input: no key association found for SA 0T\^S\^Z\^A����_/00005fb7/50
ipsec_common_input: no key association found for SA 0T\^S\^Z\^A����_/00005fb7/50

and with patch:

ipsec_common_input: no key association found for SA fe80::11/00005fb7/50
ipsec_common_input: no key association found for SA fe80::1:11/00003d59/50
ipsec_common_input: no key association found for SA fc00::11/00003d57/50
ipsec_common_input: no key association found for SA 10.9.8.11/00003d55/50
ipsec_common_input: no key association found for SA 10.9.8.11/00003d55/50

[ae]

Closed by commit rS281695 (authored by @ae).