Copter: poshold loses stray set-desired-spool-state

spool state is all handled higher up in the poshold state switch statement

ArduCopter/mode_poshold.cpp

@@ -443,9 +443,6 @@ void Copter::ModePosHold::run()
             break;
     }
 
-    // set motors to full range
-    motors->set_desired_spool_state(AP_Motors::DESIRED_THROTTLE_UNLIMITED);
-
     //
     // Shared roll & pitch states (POSHOLD_BRAKE_TO_LOITER and POSHOLD_LOITER)
     //