[dovecot/core] 2b55ff: lib: fix illumos build issue

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 2b55fff01e647e05e386b584d9018c5f5ab76e57
      https://github.com/dovecot/core/commit/2b55fff01e647e05e386b584d9018c5f5ab76e57
  Author: Josef 'Jeff' Sipek <jeff.sipek at dovecot.fi>
  Date:   2017-11-10 (Fri, 10 Nov 2017)

  Changed paths:
    M src/lib/net.c

  Log Message:
  -----------
  lib: fix illumos build issue

The recent performance improvements to the net_addr2ip() code broke
build on illumos which has a 's_addr' #define in netinit/in.h.