AP_NavEKF: replace header guard with pragma once

libraries/AP_NavEKF/AP_NavEKF.h

@@ -17,9 +17,7 @@
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-
-#ifndef AP_NavEKF
-#define AP_NavEKF
+#pragma once
 
 #include <AP_Math/AP_Math.h>
 #include <AP_InertialSensor/AP_InertialSensor.h>
@@ -300,5 +298,3 @@ private:
     AP_Int8 _gpsCheck;              // Bitmask controlling which preflight GPS checks are bypassed
 
 };
-
-#endif // AP_NavEKF

libraries/AP_NavEKF/AP_NavEKF_core.h

@@ -17,9 +17,7 @@
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-
-#ifndef AP_NavEKF_core
-#define AP_NavEKF_core
+#pragma once
 
 #include <AP_HAL/AP_HAL.h>
 #include <AP_NavEKF/AP_NavEKF.h>
@@ -875,5 +873,3 @@ private:
     // vehicle specific initial gyro bias uncertainty
     float InitialGyroBiasUncertainty(void) const;
 };
-
-#endif // AP_NavEKF_core

libraries/AP_NavEKF/AP_Nav_Common.h

@@ -15,9 +15,7 @@
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-
-#ifndef AP_Nav_Common
-#define AP_Nav_Common
+#pragma once
 
 union nav_filter_status {
     struct {
@@ -55,5 +53,3 @@ union nav_gps_status {
     } flags;
     uint16_t value;
 };
-
-#endif // AP_Nav_Common