AP_Motors: Heli: dual and quad: remove un-needed override methods

[IamPete1]

AP_MotorsHeli_Quad and AP_MotorsHeli_Dual both inherit from AP_MotorsHeli which implements the same methods. There is no need to override.

ardupilot/libraries/AP_Motors/AP_MotorsHeli.h

Lines 72 to 73 in b5e2f9a

	// has_flybar - returns true if we have a mechical flybar
	virtual bool has_flybar() const { return AP_MOTORS_HELI_NOFLYBAR; }

ardupilot/libraries/AP_Motors/AP_MotorsHeli.h

Lines 120 to 121 in b5e2f9a

	// supports_yaw_passthrough
	virtual bool supports_yaw_passthrough() const { return false; }

Alternately we could make the base class a pure virtual so the child class must implement.

[MattKear]

LGTM

[MattKear]

Just Spoken with @bnsgeyer. He is unavailable to make the call this evening so has requested that we post-pone this PR until next week.

[bnsgeyer]

LGTM