network: drop unnecessary BPF related objects from Manager when disabled

src/network/networkd-manager.c

@@ -604,7 +604,9 @@ int manager_new(Manager **ret, bool test_mode) {
                 .duid_product_uuid.type = DUID_TYPE_UUID,
                 .dhcp_server_persist_leases = true,
                 .ip_forwarding = { -1, -1, },
+#if HAVE_VMLINUX_H
                 .cgroup_fd = -EBADF,
+#endif
         };
 
         *ret = TAKE_PTR(m);

src/network/networkd-manager.h

@@ -122,12 +122,14 @@ struct Manager {
 
         /* sysctl */
         int ip_forwarding[2];
+#if HAVE_VMLINUX_H
         Hashmap *sysctl_shadow;
         sd_event_source *sysctl_event_source;
         struct ring_buffer *sysctl_buffer;
         struct sysctl_monitor_bpf *sysctl_skel;
         struct bpf_link *sysctl_link;
         int cgroup_fd;
+#endif
 };
 
 int manager_new(Manager **ret, bool test_mode);