kernel/module.c: suppress warning about unused nowarn variable

This patch fix the following warning:
kernel/module.c: In function 'add_usage_links':
kernel/module.c:1653:6: warning: variable 'nowarn' set but not used [-Wunused-but-set-variable]

[jeyu: folded in first patch since it only swapped the function order
so that del_usage_links can be called from add_usage_links]
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>

kernel/module.c

@@ -1666,31 +1666,36 @@ static inline void remove_notes_attrs(struct module *mod)
 }
 #endif /* CONFIG_KALLSYMS */
 
-static void add_usage_links(struct module *mod)
+static void del_usage_links(struct module *mod)
 {
 #ifdef CONFIG_MODULE_UNLOAD
 	struct module_use *use;
-	int nowarn;
 
 	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list) {
-		nowarn = sysfs_create_link(use->target->holders_dir,
-					   &mod->mkobj.kobj, mod->name);
-	}
+	list_for_each_entry(use, &mod->target_list, target_list)
+		sysfs_remove_link(use->target->holders_dir, mod->name);
 	mutex_unlock(&module_mutex);
 #endif
 }
 
-static void del_usage_links(struct module *mod)
+static int add_usage_links(struct module *mod)
 {
+	int ret = 0;
 #ifdef CONFIG_MODULE_UNLOAD
 	struct module_use *use;
 
 	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list)
-		sysfs_remove_link(use->target->holders_dir, mod->name);
+	list_for_each_entry(use, &mod->target_list, target_list) {
+		ret = sysfs_create_link(use->target->holders_dir,
+					&mod->mkobj.kobj, mod->name);
+		if (ret)
+			break;
+	}
 	mutex_unlock(&module_mutex);
+	if (ret)
+		del_usage_links(mod);
 #endif
+	return ret;
 }
 
 static int module_add_modinfo_attrs(struct module *mod)
@@ -1801,13 +1806,18 @@ static int mod_sysfs_setup(struct module *mod,
 	if (err)
 		goto out_unreg_param;
 
-	add_usage_links(mod);
+	err = add_usage_links(mod);
+	if (err)
+		goto out_unreg_modinfo_attrs;
+
 	add_sect_attrs(mod, info);
 	add_notes_attrs(mod, info);
 
 	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
 	return 0;
 
+out_unreg_modinfo_attrs:
+	module_remove_modinfo_attrs(mod);
 out_unreg_param:
 	module_param_sysfs_remove(mod);
 out_unreg_holders: