Sub: guided removes xy mode from calls to pos-con

Also always limit angle to maintain altitude

ArduSub/control_guided.cpp

@@ -443,7 +443,7 @@ void Sub::guided_posvel_control_run()
         pos_control.set_desired_velocity_xy(posvel_vel_target_cms.x, posvel_vel_target_cms.y);
 
         // run position controller
-        pos_control.update_xy_controller(AC_PosControl::XY_MODE_POS_AND_VEL_FF, ekfNavVelGainScaler, false);
+        pos_control.update_xy_controller(ekfNavVelGainScaler);
     }
 
     float lateral_out, forward_out;