remove unused memory transfer from TVL1 CUDA implementation

it caused runtime failures

modules/cudaoptflow/src/tvl1flow.cpp

@@ -248,7 +248,6 @@ void cv::cuda::OpticalFlowDual_TVL1_CUDA::procOneScale(const GpuMat& I0, const G
         {
             // some tweaks to make sum operation less frequently
             bool calcError = (epsilon > 0) && (n & 0x1) && (prevError < scaledEpsilon);
-            cv::Mat m1(u3);
             estimateU(I1wx, I1wy, grad, rho_c, p11, p12, p21, p22, p31, p32, u1, u2, u3, diff, l_t, static_cast<float>(theta), gamma, calcError);
             if (calcError)
             {