srogue: add and use md_fdopen().

The implementation was copied from rogue4.  Using fdopen() is necessary
because the scorefile needs both encread() and encwrite().  For some
reason I have failed to discover, one of them uses FILE *'s and the
other uses file descriptors.

srogue/mdport.c

@@ -358,6 +358,16 @@ md_unlink(char *file)
 #endif
 }
 
+FILE *
+md_fdopen(int fd, char *mode)
+{
+#ifdef _WIN32
+    return( _fdopen(fd, mode) );
+#else
+    return( fdopen(fd, mode) );
+#endif
+}
+
 int
 md_chmod(const char *filename, int mode)
 {

srogue/rip.c

@@ -145,7 +145,7 @@ int amount, aflag;
 	 */
 	if ((fd = scorefd) < 0)
 		return;
-	outf = (FILE *) fdopen(fd, "w");
+	outf = (FILE *) md_fdopen(fd, "w");
 	for (scp = top_ten; scp <= &top_ten[9]; scp++) {
 		scp->sc_score = 0;
 		for (i = 0; i < 80; i++)

srogue/rogue.h

@@ -40,6 +40,7 @@ int	md_chmod(const char *filename, int mode);
 char	*md_crypt(const char *key, const char *salt);
 int	md_dsuspchar(void);
 int	md_erasechar(void);
+FILE *	md_fdopen(int fd, char *mode);
 char	*md_gethomedir(void);
 char	*md_getusername(void);
 uid_t	md_getuid(void);