Fixing wrong label of quaternion direction

EKF/common.h

@@ -361,7 +361,7 @@ struct parameters {
 };
 
 struct stateSample {
-	Quatf  quat_nominal;	///< quaternion defining the rotation from earth to body frame
+	Quatf  quat_nominal;	///< quaternion defining the rotation from body to earth frame
 	Vector3f    vel;	///< NED velocity in earth frame in m/s
 	Vector3f    pos;	///< NED position in earth frame in m
 	Vector3f    gyro_bias;	///< delta angle bias estimate in rad

EKF/mag_fusion.cpp

@@ -537,7 +537,7 @@ void Ekf::fuseHeading()
 		H_YAW[2] = t8*t14*(-q1*t3+q1*t4+q1*t5+q1*t6-q0*q2*q3*2.0f)*2.0f;
 		H_YAW[3] = t8*t14*(q0*t3-q0*t4+q0*t5+q0*t6-q1*q2*q3*2.0f)*2.0f;
 
-		/* Calculate the 312 sequence euler angles that rotate from earth to body frame
+		/* Calculate the 312 sequence euler angles that rotate from body to earth frame
 		 * Derived from https://github.com/PX4/ecl/blob/master/matlab/scripts/Inertial%20Nav%20EKF/quat2yaw312.m
 		 * Body to nav frame transformation using a yaw-roll-pitch rotation sequence is given by:
 		 *