shared, bpf: add bpf link serialization

core: serialize socket_bind bpf links

src/core/unit.c

@@ -667,6 +667,8 @@ Unit* unit_free(Unit *u) {
         if (u->on_console)
                 manager_unref_console(u->manager);
 
+
+        fdset_free(u->initial_socket_bind_link_fds);
 #if BPF_FRAMEWORK
         bpf_link_free(u->ipv4_socket_bind_link);
         bpf_link_free(u->ipv6_socket_bind_link);