network: Stop tracking network last seen times

Drop the corresponding network_info field, function and D-Bus property.
The last seen times didn't seem useful but if a client needs them it can
probably implement the same logic with the information already available
through DBus.

src/device.c

@@ -308,9 +308,6 @@ static bool process_bss(struct device *device, struct scan_bss *bss,
 			network_get_ssid(network), security_to_str(security));
 	}
 
-	if (network_bss_list_isempty(network))
-		network_seen(network, timestamp);
-
 	network_bss_add(network, bss);
 
 	if (device->state != DEVICE_STATE_AUTOCONNECT)
@@ -1179,8 +1176,6 @@ next:
 
 	clock_gettime(CLOCK_REALTIME, &now);
 
-	network_seen(network, &now);
-
 	/* See if we have anywhere to roam to */
 	if (!best_bss || bss_match(best_bss, device->connected_bss))
 		goto fail_free_bss;

src/knownnetworks.c

@@ -180,14 +180,6 @@ static bool known_network_append_properties(
 						datestr);
 	}
 
-	if (network->seen_time.tv_sec != 0) {
-		gmtime_r(&network->seen_time.tv_sec, &tm);
-
-		if (strftime(datestr, sizeof(datestr), "%FT%TZ", &tm))
-			dbus_dict_append_string(builder, "LastSeenTime",
-						datestr);
-	}
-
 	l_dbus_message_builder_leave_array(builder);
 
 	return true;

src/network.c

@@ -109,19 +109,6 @@ static bool network_info_ptr_match(const void *a, const void *b)
 	return a == b;
 }
 
-bool network_seen(struct network *network, struct timespec *when)
-{
-	/*
-	 * Update the last seen time.  Note this is not preserved across
-	 * the network going out of range and back, or program restarts.
-	 * It may be desirable for it to be preserved in some way but
-	 * without too frequent filesystem writes.
-	 */
-	memcpy(&network->info->seen_time, when, sizeof(struct timespec));
-
-	return true;
-}
-
 void network_connected(struct network *network)
 {
 	int err;

src/network.h

@@ -28,7 +28,6 @@ struct device;
 struct network;
 struct scan_bss;
 
-bool network_seen(struct network *network, struct timespec *when);
 void network_connected(struct network *network);
 void network_disconnected(struct network *network);
 bool network_rankmod(const struct network *network, double *rankmod);