AP_AHRS_DCM: limit measured airspeed according to WIND_MAX

libraries/AP_AHRS/AP_AHRS_DCM.cpp

@@ -1048,23 +1048,19 @@ bool AP_AHRS_DCM::get_position(struct Location &loc) const
 // return an airspeed estimate if available
 bool AP_AHRS_DCM::airspeed_estimate(float &airspeed_ret) const
 {
-    bool ret = false;
     if (airspeed_sensor_enabled()) {
         airspeed_ret = _airspeed->get_airspeed();
-        return true;
-    }
-
-    if (!_flags.wind_estimation) {
-        return false;
-    }
-
-    // estimate it via GPS speed and wind
-    if (have_gps()) {
+    } else if (_flags.wind_estimation && have_gps()) {
+        // estimate it via GPS speed and wind
+        airspeed_ret = _last_airspeed;
+    } else {
+        // give the last estimate, but return false. This is used by
+        // dead-reckoning code
         airspeed_ret = _last_airspeed;
-        ret = true;
+        return false;
     }
 
-    if (ret && _wind_max > 0 && AP::gps().status() >= AP_GPS::GPS_OK_FIX_2D) {
+    if (_wind_max > 0 && AP::gps().status() >= AP_GPS::GPS_OK_FIX_2D) {
         // constrain the airspeed by the ground speed
         // and AHRS_WIND_MAX
         const float gnd_speed = AP::gps().ground_speed();
@@ -1074,12 +1070,8 @@ bool AP_AHRS_DCM::airspeed_estimate(float &airspeed_ret) const
                                         gnd_speed + _wind_max);
         airspeed_ret = true_airspeed / get_EAS2TAS();
     }
-    if (!ret) {
-        // give the last estimate, but return false. This is used by
-        // dead-reckoning code
-        airspeed_ret = _last_airspeed;
-    }
-    return ret;
+
+    return true;
 }
 
 bool AP_AHRS_DCM::set_home(const Location &loc)