remove SYSFLAGS and MFLOPPY code

A check into github issue 364 confirmed that
ba6edbe5dc
had incorrectly updated the bwrite sizeof entry for sysflags.

The SYSFLAGS and MFLOPPY code is all in the outdated part of the tree, so just
remove it rather than re-correct it.

Closes #364
Closes #207

src/do.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	do.c	$NHDT-Date: 1588191740 2020/04/29 20:22:20 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.243 $ */
+/* NetHack 3.6	do.c	$NHDT-Date: 1593953347 2020/07/05 12:49:07 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.246 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1157,9 +1157,6 @@ currentlevel_rewrite()
 {
     NHFILE *nhfp;
     char whynot[BUFSZ];
-#ifdef MFLOPPY
-    int savemode;
-#endif
 
     /* since level change might be a bit slow, flush any buffered screen
      *  output (like "you fall through a trap door") */
@@ -1178,18 +1175,6 @@ currentlevel_rewrite()
         return (NHFILE *) 0;
     }
 
-#ifdef MFLOPPY
-    savemode = nhfp->mode;
-    nhfp->mode = COUNTING;
-    if (!savelev(nhfp, ledger_no(&u.uz))) {
-        close_nhfile(nhfp);
-        delete_levelfile(ledger_no(&u.uz));
-        pline("NetHack is out of disk space for making levels!");
-        You("can save, quit, or continue playing.");
-        return -1;
-    }
-    nhfp->mode = savemode;
-#endif
     return nhfp;
 }