message: Incorrect kernel matrix size when Scharr
  Incorrect Mat size ksize==-1
diff: @@ -1026,8 +1026,8 @@ GAPI_FLUID_KERNEL(GFluidSobel, cv::gapi::imgproc::GSobel, true)
  auto *kx = scratch.OutLine<float>();
  auto *ky = kx + ksz;
  - Mat kxmat(1, ksize, CV_32FC1, kx);
  - Mat kymat(ksize, 1, CV_32FC1, ky);
  + Mat kxmat(1, ksz, CV_32FC1, kx);
  + Mat kymat(ksz, 1, CV_32FC1, ky);
  getDerivKernels(kxmat, kymat, dx, dy, ksize);
  }
  @@ -1185,12 +1185,12 @@ GAPI_FLUID_KERNEL(GFluidSobelXY, cv::gapi::imgproc::GSobelXY, true)
  auto *kx_dy = buf_helper.kx_dy;
  auto *ky_dy = buf_helper.ky_dy;
  - Mat kxmatX(1, ksize, CV_32FC1, kx_dx);
  - Mat kymatX(ksize, 1, CV_32FC1, ky_dx);
  + Mat kxmatX(1, ksz, CV_32FC1, kx_dx);
  + Mat kymatX(ksz, 1, CV_32FC1, ky_dx);
  getDerivKernels(kxmatX, kymatX, order, 0, ksize);
  - Mat kxmatY(1, ksize, CV_32FC1, kx_dy);
  - Mat kymatY(ksize, 1, CV_32FC1, ky_dy);
  + Mat kxmatY(1, ksz, CV_32FC1, kx_dy);
  + Mat kymatY(ksz, 1, CV_32FC1, ky_dy);
  getDerivKernels(kxmatY, kymatY, 0, order, ksize);
  }
  