Cleanup ddebug submodule

Remove unused functions.

ddebug/debug.cpp

@@ -1,55 +0,0 @@
-/*
- * Descent 3
- * Copyright (C) 2024 Parallax Software
- * Copyright (C) 2024 Descent Developers
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <cstdio>
-#include <cstdlib>
-#include <cstring>
-
-#include "debug.h"
-
-void Debug_LogClose();
-
-FILE *Debug_logfile = nullptr;
-
-bool Debug_Logfile(const char *filename) {
-  if (Debug_logfile == nullptr) {
-    Debug_logfile = fopen(filename, "w");
-    if (Debug_logfile == nullptr) {
-      Debug_MessageBox(OSMBOX_OK, "Debug", "FYI Logfile couldn't be created.");
-      return false;
-    }
-    atexit(Debug_LogClose);
-  }
-  Debug_LogWrite("BEGINNING LOG\n\n");
-
-  return true;
-}
-
-void Debug_LogWrite(const char *str) {
-  if (Debug_logfile)
-    fwrite(str, strlen(str), 1, Debug_logfile);
-}
-
-void Debug_LogClose() {
-  if (Debug_logfile) {
-    Debug_LogWrite("\nEND LOG");
-    fclose(Debug_logfile);
-    Debug_logfile = nullptr;
-  }
-}