AC_AttitudeControl: fix reset_target_and_rate method

[IamPete1]

This method is resetting the euler angle target not the euler rate target. It also only updates the _attitude_target quaternion so the euler is not up to date.

The only users that have reset_rate true are in copter acro while in shut down or ground idle:

ardupilot/ArduCopter/mode_acro.cpp

Lines 34 to 46 in 1d08662

	case AP_Motors::SpoolState::SHUT_DOWN:
	// Motors Stopped
	attitude_control->reset_target_and_rate(true);
	attitude_control->reset_rate_controller_I_terms();
	pilot_desired_throttle = 0.0f;
	break;
	case AP_Motors::SpoolState::GROUND_IDLE:
	// Landed
	attitude_control->reset_target_and_rate();
	attitude_control->reset_rate_controller_I_terms_smoothly();
	pilot_desired_throttle = 0.0f;
	break;

[lthall]

Nice catch!!

[rmackay9]

@IamPete1,

Thanks for this. It's been tested of course?
I've marked this for backporting to 4.5.

[lthall]

This is a difficult thing to test because it doesn't really change anything other than making the code correct.

Both the Euler angle and rates get reset to the quaternion and angular velocity values in the code. I think the only detectable difference will be a single loop where the euler values aren't reset properly.

Thinking about it this probably makes all the attitude target logs correct during ground idle where before they may have been zero. Even that may have already been overridden already though.

[rmackay9]

OK, in it goes. Thanks!