voted_sensors_update: make msl_pressure static const

src/modules/sensors/voted_sensors_update.cpp

@@ -50,6 +50,9 @@
 using namespace sensors;
 using namespace DriverFramework;
 
+
+const double VotedSensorsUpdate::_msl_pressure = 101.325f;
+
 VotedSensorsUpdate::VotedSensorsUpdate(const Parameters &parameters)
 	: _parameters(parameters)
 {
@@ -816,10 +819,10 @@ void VotedSensorsUpdate::baro_poll(struct sensor_combined_s &raw)
 			const double R  = 287.05;	/* ideal gas constant in J/kg/K */
 
 			/* current pressure at MSL in kPa */
-			double p1 = _msl_pressure / 1000.0;
+			const double p1 = _msl_pressure;
 
 			/* measured pressure in kPa */
-			double p = 0.001f * _last_best_baro_pressure;
+			const double p = 0.001f * _last_best_baro_pressure;
 
 			/*
 			 * Solve:

src/modules/sensors/voted_sensors_update.h

@@ -276,9 +276,7 @@ private:
 	float _baro_offset[SENSOR_COUNT_MAX]; /**< offsets to be added to the raw baro pressure data after scale factor correction */
 	float _baro_scale[SENSOR_COUNT_MAX]; /**< scale factor corrections to be applied to the raw barp pressure data before offsets are added */
 
-	/* altitude conversion calibration */
-	unsigned		_msl_pressure;	/* in Pa */
-
+	static const double	_msl_pressure;	/** average sea-level pressure in kPa */
 };