EKF: update vertical position and velocity reset capture

Use reset event struct members instead of separate variables

EKF/ekf.cpp

@@ -107,10 +107,6 @@ Ekf::Ekf():
 	_gps_hgt_faulty(false),
 	_rng_hgt_faulty(false),
 	_baro_hgt_offset(0.0f),
-	_vert_pos_reset_delta(0.0f),
-	_time_vert_pos_reset(0),
-	_vert_vel_reset_delta(0.0f),
-	_time_vert_vel_reset(0),
 	_time_bad_vert_accel(0)
 {
 	_state = {};