Add missing free of NetworkInstanceStatus

From comments in #2285

Signed-off-by: eriknordmark <erik@zededa.com>

pkg/pillar/cmd/zedrouter/zedrouter.go

@@ -1930,6 +1930,14 @@ func doAppNetworkModifyUNetAppNum(
 		log.Error(err)
 		return err
 	}
+	// Did the freeAppIntfNum release any last reference?
+	netstatus := lookupNetworkInstanceStatus(ctx, ulStatus.Network.String())
+	if netstatus != nil {
+		if maybeNetworkInstanceDelete(ctx, netstatus) {
+			log.Functionf("post freeAppIntfNum(%v) for %s deleted %s",
+				oldNetworkID, appID, netstatus.Key())
+		}
+	}
 	return nil
 }
 
@@ -1982,7 +1990,7 @@ func handleDelete(ctx *zedrouterContext, key string,
 		netstatus := lookupNetworkInstanceStatus(ctx, ulStatus.Network.String())
 		if netstatus != nil {
 			if maybeNetworkInstanceDelete(ctx, netstatus) {
-				log.Functionf("post appNumsOnUNetFree(%v) for %s deleted %s",
+				log.Functionf("post freeAppIntfNums(%v) for %s deleted %s",
 					status.UUIDandVersion, status.DisplayName,
 					netstatus.Key())
 			}