Solaris broken

Commit a893edc7 broke Solaris.

../../ntpd/ntp_io.c: In function 'read_network_packet':
../../ntpd/ntp_io.c:2329:8: error: 'struct msghdr' has no member named 'msg_flags'
  msghdr.msg_flags      = 0;
        ^
../../ntpd/ntp_io.c:2330:8: error: 'struct msghdr' has no member named 'msg_control'
  msghdr.msg_control    = (void *)&control;
        ^
../../ntpd/ntp_io.c:2331:8: error: 'struct msghdr' has no member named 'msg_controllen'
  msghdr.msg_controllen = sizeof(control);
        ^

Commit 7445a835 fixes the msg_flags.