difftool: eliminate use of USE_THE_REPOSITORY_VARIABLE

Remove the USE_THE_REPOSITORY_VARIABLE #define now that all
state is passed to each function from callers.

Signed-off-by: David Aguilar <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: davvid

builtin/difftool.c

@@ -12,8 +12,6 @@
  * Copyright (C) 2016 Johannes Schindelin
  */
 
-#define USE_THE_REPOSITORY_VARIABLE
-
 #include "builtin.h"
 
 #include "abspath.h"