cleanup: remove unused git_checkout_config

Directly call git_default_config instead.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-checkout.c

@@ -484,11 +484,6 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 	return post_checkout_hook(old.commit, new->commit, 1);
 }
 
-static int git_checkout_config(const char *var, const char *value)
-{
-	return git_default_config(var, value);
-}
-
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
 	struct checkout_opts opts;
@@ -510,7 +505,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	memset(&opts, 0, sizeof(opts));
 	memset(&new, 0, sizeof(new));
 
-	git_config(git_checkout_config);
+	git_config(git_default_config);
 
 	opts.track = git_branch_track;