remove systemd support

systemd people are not willing to play nice with the rest of the world.
Therefore there is no reason for the rest of the world to cooperate with them.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

sysklogd/syslogd.c

@@ -936,11 +936,6 @@ static NOINLINE int create_socket(void)
 	int sock_fd;
 	char *dev_log_name;
 
-#if ENABLE_FEATURE_SYSTEMD
-	if (sd_listen_fds() == 1)
-		return SD_LISTEN_FDS_START;
-#endif
-
 	memset(&sunx, 0, sizeof(sunx));
 	sunx.sun_family = AF_UNIX;