Using new xpdev-defined _PATH_DEVNULL macro.

src/sbbs3/sbbscon.c

@@ -769,7 +769,7 @@ daemon(nochdir, noclose)
     if (!nochdir)
         (void)chdir("/");
 
-    if (!noclose && (fd = open("/dev/null", O_RDWR, 0)) != -1) {
+    if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
         (void)dup2(fd, STDIN_FILENO);
         (void)dup2(fd, STDOUT_FILENO);
         (void)dup2(fd, STDERR_FILENO);