pipewire: impl-module: respect PIPEWIRE_DLCLOSE

Commit b5c21c1fbc ("pipewire: use dlclose unless PIPEWIRE_DLCLOSE is set to false")
introduced the PIPEWIRE_DLCLOSE environmental variable to
force/prevent the dlclose()ing of shared objects. However,
native pipewire modules were not adjusted to respect its value,
and instead have been still using `pw_in_valgrind()` to
determine whether or not they should be unloaded.

Fix that by adding a private `pw_should_dlclose()` function
and using that in impl-module.c:pw_impl_module_destroy().

src/pipewire/impl-module.c

@@ -323,7 +323,7 @@ void pw_impl_module_destroy(struct pw_impl_module *module)
 		pw_work_queue_cancel(pw_context_get_work_queue(module->context),
 				     module, SPA_ID_INVALID);
 
-	if (!pw_in_valgrind() && dlclose(impl->hnd) != 0)
+	if (pw_should_dlclose() && dlclose(impl->hnd) != 0)
 		pw_log_warn("%p: dlclose failed: %s", module, dlerror());
 	free(impl);
 }

src/pipewire/pipewire.c

@@ -149,7 +149,7 @@ unref_plugin(struct plugin *plugin)
 	if (--plugin->ref == 0) {
 		spa_list_remove(&plugin->link);
 		pw_log_debug("unloaded plugin:'%s'", plugin->filename);
-		if (global_support.do_dlclose)
+		if (pw_should_dlclose())
 			dlclose(plugin->hnd);
 		free(plugin->filename);
 		free(plugin);
@@ -791,6 +791,12 @@ bool pw_in_valgrind(void)
 	return global_support.in_valgrind;
 }
 
+bool
+pw_should_dlclose(void)
+{
+	return global_support.do_dlclose;
+}
+
 SPA_EXPORT
 bool pw_check_option(const char *option, const char *value)
 {

src/pipewire/private.h

@@ -1292,6 +1292,8 @@ void pw_settings_init(struct pw_context *context);
 int pw_settings_expose(struct pw_context *context);
 void pw_settings_clean(struct pw_context *context);
 
+bool pw_should_dlclose(void);
+
 /** \endcond */
 
 #ifdef __cplusplus