Copter: consider health of primary compass in SYS_STATUS, pre-arm and compassmot

this should prevent users from taking off with only secondary compass

ArduCopter/GCS_Mavlink.pde

@@ -185,7 +185,7 @@ static NOINLINE void send_extended_status1(mavlink_channel_t chan)
 
     // default to all healthy except compass, gps and receiver which we set individually
     control_sensors_health = control_sensors_present & (~MAV_SYS_STATUS_SENSOR_3D_MAG & ~MAV_SYS_STATUS_SENSOR_GPS & ~MAV_SYS_STATUS_SENSOR_RC_RECEIVER);
-    if (g.compass_enabled && compass.healthy() && ahrs.use_compass()) {
+    if (g.compass_enabled && compass.healthy(0) && ahrs.use_compass()) {
         control_sensors_health |= MAV_SYS_STATUS_SENSOR_3D_MAG;
     }
     if (g_gps != NULL && g_gps->status() > GPS::NO_GPS && (!gps_glitch.glitching()||ap.usb_connected)) {

ArduCopter/compassmot.pde

@@ -38,7 +38,7 @@ static uint8_t mavlink_compassmot(mavlink_channel_t chan)
 
     // check compass health
     compass.read();
-    if (!compass.healthy()) {
+    if (!compass.healthy(0)) {
         gcs[chan-MAVLINK_COMM_0].send_text_P(SEVERITY_HIGH, PSTR("check compass"));
         ap.compass_mot = false;
         return 1;
@@ -128,7 +128,7 @@ static uint8_t mavlink_compassmot(mavlink_channel_t chan)
     last_send_time = millis();
 
     // main run while there is no user input and the compass is healthy
-    while (command_ack_start == command_ack_counter && compass.healthy() && motors.armed()) {
+    while (command_ack_start == command_ack_counter && compass.healthy(0) && motors.armed()) {
         // 50hz loop
         if (millis() - last_run_time < 20) {
             // grab some compass values

ArduCopter/motors.pde

@@ -248,7 +248,7 @@ static void pre_arm_checks(bool display_failure)
     // check Compass
     if ((g.arming_check == ARMING_CHECK_ALL) || (g.arming_check & ARMING_CHECK_COMPASS)) {
         // check the compass is healthy
-        if(!compass.healthy()) {
+        if(!compass.healthy(0)) {
             if (display_failure) {
                 gcs_send_text_P(SEVERITY_HIGH,PSTR("PreArm: Compass not healthy"));
             }