commit: factor status configuration is a helper function

cmd_commit and cmd_status use very similar code to initialize the
wt_status structure. Factor this code into a function to ensure future
changes will keep both versions consistent.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/commit.c b/builtin/commit.c
index 10acc53..94512c0 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -163,6 +163,14 @@
 		s->whence = whence;
 }
 
+static void status_init_config(struct wt_status *s, config_fn_t fn)
+{
+	wt_status_prepare(s);
+	gitmodules_config();
+	git_config(fn, s);
+	determine_whence(s);
+}
+
 static void rollback_index_files(void)
 {
 	switch (commit_style) {
@@ -1246,10 +1254,7 @@
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(builtin_status_usage, builtin_status_options);
 
-	wt_status_prepare(&s);
-	gitmodules_config();
-	git_config(git_status_config, &s);
-	determine_whence(&s);
+	status_init_config(&s, git_status_config);
 	argc = parse_options(argc, argv, prefix,
 			     builtin_status_options,
 			     builtin_status_usage, 0);
@@ -1492,11 +1497,8 @@
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(builtin_commit_usage, builtin_commit_options);
 
-	wt_status_prepare(&s);
-	gitmodules_config();
-	git_config(git_commit_config, &s);
+	status_init_config(&s, git_commit_config);
 	status_format = STATUS_FORMAT_NONE; /* Ignore status.short */
-	determine_whence(&s);
 	s.colopts = 0;
 
 	if (get_sha1("HEAD", sha1))