checkout: pass whole struct to parse_branchname_arg instead of individual flags

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -1079,11 +1079,12 @@ static void check_linked_checkouts(struct branch_info *new)
 static int parse_branchname_arg(int argc, const char **argv,
 				int dwim_new_local_branch_ok,
 				struct branch_info *new,
-				struct tree **source_tree,
-				unsigned char rev[20],
-				const char **new_branch,
-				int force_detach)
+				struct checkout_opts *opts,
+				unsigned char rev[20])
 {
+	struct tree **source_tree = &opts->source_tree;
+	const char **new_branch = &opts->new_branch;
+	int force_detach = opts->force_detach;
 	int argcount = 0;
 	unsigned char branch_rev[20];
 	const char *arg;
@@ -1420,9 +1421,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			opts.track == BRANCH_TRACK_UNSPECIFIED &&
 			!opts.new_branch;
 		int n = parse_branchname_arg(argc, argv, dwim_ok,
-					     &new, &opts.source_tree,
-					     rev, &opts.new_branch,
-					     opts.force_detach);
+					     &new, &opts, rev);
 		argv += n;
 		argc -= n;
 	}