string_list: remove string_list_insert_at_index() from its API

There no longer is a caller to this function.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: stefanbeller

string-list.c

@@ -59,13 +59,7 @@ static int add_entry(int insert_at, struct string_list *list, const char *string
 
 struct string_list_item *string_list_insert(struct string_list *list, const char *string)
 {
-	return string_list_insert_at_index(list, -1, string);
-}
-
-struct string_list_item *string_list_insert_at_index(struct string_list *list,
-						     int insert_at, const char *string)
-{
-	int index = add_entry(insert_at, list, string);
+	int index = add_entry(-1, list, string);
 
 	if (index < 0)
 		index = -1 - index;

string-list.h

@@ -61,8 +61,6 @@ int string_list_find_insert_index(const struct string_list *list, const char *st
  * Returns the string_list_item, the string is part of.
  */
 struct string_list_item *string_list_insert(struct string_list *list, const char *string);
-struct string_list_item *string_list_insert_at_index(struct string_list *list,
-						     int insert_at, const char *string);
 
 /*
  * Checks if the given string is part of a sorted list. If it is part of the list,