mavlink_system: set update_counter for safe points

This variable was not set and lead to uninitialized memory being written
to dataman.

src/modules/mavlink/mavlink_mission.cpp

@@ -62,6 +62,8 @@ int32_t MavlinkMissionManager::_current_seq = 0;
 bool MavlinkMissionManager::_transfer_in_progress = false;
 constexpr uint16_t MavlinkMissionManager::MAX_COUNT[];
 uint16_t MavlinkMissionManager::_geofence_update_counter = 0;
+uint16_t MavlinkMissionManager::_safepoint_update_counter = 0;
+
 
 #define CHECK_SYSID_COMPID_MISSION(_msg)		(_msg.target_system == mavlink_system.sysid && \
 		((_msg.target_component == mavlink_system.compid) || \
@@ -236,6 +238,7 @@ MavlinkMissionManager::update_safepoint_count(unsigned count)
 {
 	mission_stats_entry_s stats;
 	stats.num_items = count;
+	stats.update_counter = ++_safepoint_update_counter;
 
 	/* update stats in dataman */
 	int res = dm_write(DM_KEY_SAFE_POINTS, 0, DM_PERSIST_POWER_ON_RESET, &stats, sizeof(mission_stats_entry_s));

src/modules/mavlink/mavlink_mission.h

@@ -130,6 +130,7 @@ private:
 	orb_advert_t		_offboard_mission_pub{nullptr};
 
 	static uint16_t		_geofence_update_counter;
+	static uint16_t		_safepoint_update_counter;
 	bool			_geofence_locked{false};		///< if true, we currently hold the dm_lock for the geofence (transaction in progress)
 
 	MavlinkRateLimiter	_slow_rate_limiter{100 * 1000};		///< Rate limit sending of the current WP sequence to 10 Hz