AP_Arming: use new enum for home_is_set

libraries/AP_Arming/AP_Arming.cpp

@@ -47,7 +47,7 @@ const AP_Param::GroupInfo AP_Arming::var_info[] PROGMEM = {
 //The function point is particularly hacky, hacky, tacky
 //but I don't want to reimplement messaging to GCS at the moment:
 AP_Arming::AP_Arming(const AP_AHRS &ahrs_ref, const AP_Baro &baro, Compass &compass,
-                     const bool &home_set, gcs_send_t_p gcs_print_func)
+                     const enum HomeState &home_set, gcs_send_t_p gcs_print_func)
     : armed(false)
    , logging_available(false)
    , skip_gyro_cal(false)
@@ -259,7 +259,7 @@ bool AP_Arming::gps_checks(bool report)
         const AP_GPS &gps = ahrs.get_gps();
 
         //GPS OK?
-        if (!home_is_set || 
+        if (home_is_set == HOME_UNSET || 
             gps.status() < AP_GPS::GPS_OK_FIX_3D ||              
             AP_Notify::flags.gps_glitching ||
             AP_Notify::flags.failsafe_gps) {

libraries/AP_Arming/AP_Arming.h

@@ -41,7 +41,7 @@ public:
     typedef void (*gcs_send_t_p)(gcs_severity, const prog_char_t*);
 
     AP_Arming(const AP_AHRS &ahrs_ref, const AP_Baro &baro, Compass &compass,
-              const bool &home_set, gcs_send_t_p);
+              const enum HomeState &home_set, gcs_send_t_p);
 
     ArmingRequired arming_required();
     bool arm(uint8_t method);
@@ -75,7 +75,7 @@ private:
     const AP_AHRS                                       &ahrs;
     const AP_Baro                                  &barometer;
     Compass                                         &_compass;
-    const bool                                   &home_is_set;
+    const enum HomeState                         &home_is_set;
     gcs_send_t_p                              gcs_send_text_P;
 
     void set_enabled_checks(uint16_t);