TopK BUG2 fix

source/tensor/core/sort/TopK.cu

@@ -871,7 +871,7 @@ void _CudaTopK(const XTensor * a, XTensor * b, XTensor * index, int dim, int k)
         //delete indexA;
         int workerNum = WORKERSNUM;
 
-        GDevs.GetCudaThread2D(a->mem->devID,
+        GDevs.GetCudaThread2D(a->devID,
             workerNum, stride * blockNum, MAX_INT,
             cudaGrids, cudaBlocks);
         if (a->dataType == DEFAULT_DTYPE) {