AP_WindVane: fix typo on record_home_heading

libraries/AP_WindVane/AP_WindVane.cpp

@@ -164,7 +164,7 @@ float AP_WindVane::get_apparent_wind_direction_rad() const
 }
 
 // record home heading for use as wind direction if no sensor is fitted
-void AP_WindVane::record_home_headng()
+void AP_WindVane::record_home_heading()
 {
     _home_heading = AP::ahrs().yaw;
 }

libraries/AP_WindVane/AP_WindVane.h

@@ -53,7 +53,7 @@ public:
     float get_apparent_wind_direction_rad() const;
 
     // record home heading
-    void record_home_headng();
+    void record_home_heading();
 
     // start calibration routine
     bool start_calibration();