AP_BattMonitor_logging: update to use capacity_remaining_pct() as a bool

libraries/AP_BattMonitor/AP_BattMonitor_Logging.cpp

@@ -7,6 +7,8 @@ extern const AP_HAL::HAL& hal;
 void AP_BattMonitor_Backend::Log_Write_BAT(const uint8_t instance, const uint64_t time_us) const
 {
     bool has_curr = has_current();
+    uint8_t percent = -1;
+    IGNORE_RETURN(capacity_remaining_pct(percent));
 
     const struct log_BAT pkt{
         LOG_PACKET_HEADER_INIT(LOG_BAT_MSG),
@@ -19,7 +21,7 @@ void AP_BattMonitor_Backend::Log_Write_BAT(const uint8_t instance, const uint64_
         consumed_wh         : has_curr ? _state.consumed_wh : AP::logger().quiet_nanf(),
         temperature         : (int16_t) ( has_temperature() ? _state.temperature * 100 : 0),
         resistance          : _state.resistance,
-        rem_percent         : capacity_remaining_pct(),
+        rem_percent         : percent,
     };
     AP::logger().WriteBlock(&pkt, sizeof(pkt));
 }