Revert "Older Linux installations do not have svcfd_create()."

This reverts commit 44e384aedb.

This code is actually needed.  If svcfd_create() is not available, it
should be fixed only for those systems that it affects.

cde/lib/tt/slib/mp_rpc_server.C

@@ -120,7 +120,6 @@ init(void (*service_fn)(struct svc_req *, SVCXPRT *))
 	unsigned int buffersize = (bufopt != (char *)0) ? atoi(bufopt) : 32000;
 
 	if (_socket != RPC_ANYSOCK) {
-#ifdef OPT_UNIX_SOCKET_RPC
 		_transp = svcfd_create(_socket, buffersize, buffersize);
 		if (_transp == (SVCXPRT *)0) {
 			return(0);
@@ -131,7 +130,6 @@ init(void (*service_fn)(struct svc_req *, SVCXPRT *))
 			_tt_syslog(0, LOG_ERR, "svc_register(): %m");
 			return(0);
 		}
-#endif
 
 		return(1);
 	}