acc(k): Remove double #define.

Remove definition of ACC_CORE_LEN in acc.h, it's part of acc_api.h
nowadays.

modules_k/acc/acc.h

@@ -41,8 +41,6 @@
 #ifndef _ACC_ACC_H_
 #define _ACC_ACC_H_
 
-#define ACC_CORE_LEN 6
-
 /* leading text for a request accounted from a script */
 #define ACC "ACC: "
 #define ACC_REQUEST ACC"request accounted: "