pipewire: module-profiler: destroy event source

Even though all event sources are kept in a list in the current
implementation of the event loop in the SPA support plugin, relying
on it freeing all sources could lead to unbounded memory use
if the profiler module is loaded and unloaded over and over again.

src/modules/module-profiler.c

@@ -346,6 +346,8 @@ static void module_destroy(void *data)
 
 	pw_properties_free(impl->properties);
 
+	pw_loop_destroy_source(pw_context_get_main_loop(impl->context), impl->flush_timeout);
+
 	free(impl);
 }