network: remove unnecessary fd saved in fd-store

Fixes the following warning:
```
[  130.968170] H systemd-networkd[4288]: Restart operation initiated.
[  130.968265] H systemd-networkd[4288]: Serializing...
[  130.968274] H systemd-networkd[4288]: There is nothing to serialize.
(snip)
[  130.978756] H systemd[1]: Stopped systemd-networkd.service.
(snip)
[  130.991407] H systemd[1]: Starting systemd-networkd.service...
(snip)
[  131.077440] H systemd-networkd[4318]: Enumeration completed.
[  131.077471] H systemd-networkd[4318]: Deserializing...
[  131.077491] H systemd-networkd[4318]: Failed to parse json (line=0, column=0): No data available
[  131.077524] H systemd-networkd[4318]: Failed to deserialize the previous invocation, ignoring: No data available
```

(cherry picked from commit 13852e1914a6d6515eaf5857470ca8a11fdbacd4)

diff --git a/src/network/networkd-serialize.c b/src/network/networkd-serialize.c
index 26a38bd4dde885e8ecaee195ace2d0a4c9c307d2..a04d47c52b4330d6da9229aca3ae3c6c2eebbaa6 100644 (file)
--- a/src/network/networkd-serialize.c
+++ b/src/network/networkd-serialize.c
@@ -60,6 +60,7 @@ int manager_serialize(Manager *manager) {
 
         if (!v) {
                 log_debug("There is nothing to serialize.");
+                (void) notify_remove_fd_warn("manager-serialization");
                 return 0;
         }