Crash in stereo_dft_generate_comfort_noise_fx at 24k4

with 1670c2bf and this bitstream G3S5.c01_-stereo_-dtx_24400_48.bit, we got a crash in the function stereo_dft_generate_comfort_noise_fx()

This file was ok yesterday

maybe related to #756 (closed)

        IF( LT_16( hStereoCng->xfade_frame_counter, hStereoCng->xfade_length ) )
        {
            ptr_cng = cngNoiseLevel_hist + hFdCngCom->startBand;
            ptr_tmp = cngNoiseLevel_upd + hFdCngCom->startBand;
            FOR( i = 0; i < shr( sub( st->last_L_frame, hFdCngCom->startBand ), 1 ); i++ )
            {
                q_sqrt = st->hFdCngDec->bandNoiseShape_exp;
                move16();
                tmp_16 = BASOP_Util_Divide1616_Scale( hStereoCng->xfade_frame_counter, hStereoCng->xfade_length, &q_div );
                tmp_16 = shl( tmp_16, q_div );
                tmp = Sqrt32( *ptr_cng++, &q_sqrt );
         -->>>> tmp = L_shl( tmp, sub( add( q_cngNoiseLevel_upd, q_sqrt ), 31 ) );
                *ptr_tmp = L_add( Mpy_32_16_1( *ptr_tmp, tmp_16 ), Mpy_32_16_1( Mpy_32_16_1( tmp, sub( MAX_16, tmp_16 ) ), hStereoDft->scale_fx ) );
                move32();
                ptr_tmp++;
            }
        }