add SPA_EXPORT where needed

src/modules/spa/module-monitor.c

@@ -52,6 +52,7 @@ const struct pw_module_events module_events = {
 	.destroy = module_destroy,
 };
 
+SPA_EXPORT
 int pipewire__module_init(struct pw_module *module, const char *args)
 {
 	const char *dir;

src/modules/spa/module-node-factory.c

@@ -196,6 +196,7 @@ static int module_init(struct pw_module *module, struct pw_properties *propertie
 	return 0;
 }
 
+SPA_EXPORT
 int pipewire__module_init(struct pw_module *module, const char *args)
 {
 	return module_init(module, NULL);

src/modules/spa/module-node.c

@@ -53,6 +53,7 @@ static const struct pw_module_events module_events = {
 	.destroy = module_destroy,
 };
 
+SPA_EXPORT
 int pipewire__module_init(struct pw_module *module, const char *args)
 {
 	struct pw_properties *props = NULL;