MAX_VAR_NAME isn't used anywhere, remove it.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: yaboot/second/cfg.c
===================================================================
--- yaboot.orig/second/cfg.c	2010-07-08 14:19:06.000000000 +1000
+++ yaboot/second/cfg.c	2010-07-08 14:19:47.000000000 +1000
@@ -42,7 +42,6 @@ typedef struct {
 } CONFIG;
 
 #define MAX_TOKEN 511
-#define MAX_VAR_NAME MAX_TOKEN
 #define EOF -1
 
 CONFIG cf_options[] =