diffcore-delta: remove unused parameter to diffcore_count_changes()

The delta_limit parameter to diffcore_count_changes() has been unused
since commit ba23bbc8e ("diffcore-delta: make change counter to byte
oriented again.", 2006-03-04).

Remove the parameter and adjust all callers.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diffcore-break.c

@@ -73,7 +73,6 @@ static int should_break(struct diff_filespec *src,
 
 	if (diffcore_count_changes(src, dst,
 				   &src->cnt_data, &dst->cnt_data,
-				   0,
 				   &src_copied, &literal_added))
 		return 0;