syslogd: cleanup

- remove flag macros
- remove some unecessary gotos
- inline open_udp_socks() and getport()
- simplify resulting open_logfiles()
  Now in the syslog.conf the port numbers for remote hosts are no
  longer allowed to be hexadecimal. If there is need for hexadecimal
  port numbers, one can as well accept octal ones and use base 0
  in strtoul.