AP_TECS: use ins singleton

libraries/AP_TECS/AP_TECS.cpp

@@ -325,7 +325,7 @@ void AP_TECS::update_50hz(void)
     // Get DCM
     const Matrix3f &rotMat = _ahrs.get_rotation_body_to_ned();
     // Calculate speed rate of change
-    float temp = rotMat.c.x * GRAVITY_MSS + _ahrs.get_ins().get_accel().x;
+    float temp = rotMat.c.x * GRAVITY_MSS + AP::ins().get_accel().x;
     // take 5 point moving average
     _vel_dot = _vdot_filter.apply(temp);