fix the number of perf algo for conv cudnn in exhaustive mode (#28694)

paddle/fluid/operators/conv_cudnn_helper.h

@@ -429,7 +429,7 @@ struct SearchAlgorithm<cudnnConvolutionBwdDataAlgoPerf_t> {
           x_dims, w_dims, args.s, args.p, args.d, 0,
           static_cast<int64_t>(args.cudnn_dtype), [&]() {
             int returned_algo_count;
-            std::array<perf_t, kNUM_CUDNN_FWD_ALGS> perf_stat;
+            std::array<perf_t, kNUM_CUDNN_BWD_DATA_ALGS> perf_stat;
 
             auto cudnn_find_func = [&](void* cudnn_workspace_ptr) {
               PADDLE_ENFORCE_CUDA_SUCCESS(
@@ -561,7 +561,7 @@ struct SearchAlgorithm<cudnnConvolutionBwdFilterAlgoPerf_t> {
             x_dims, w_dims, args.s, args.p, args.d, 0,
             static_cast<int64_t>(args.cudnn_dtype), [&]() {
               int returned_algo_count;
-              std::array<perf_t, kNUM_CUDNN_FWD_ALGS> perf_stat;
+              std::array<perf_t, kNUM_CUDNN_BWD_FILTER_ALGS> perf_stat;
               auto cudnn_find_func = [&](void* cudnn_workspace_ptr) {
                 PADDLE_ENFORCE_CUDA_SUCCESS(
                     platform::dynload::