Fix val warning (#74468)

Author: co63oc

paddle/phi/kernels/impl/accuracy_check_kernel_impl.h

@@ -108,7 +108,7 @@ struct AccuracyCheckFunctor<phi::CPUContext, phi::dtype::complex<T>> {
     for (int i = 0; i < num; i++) {
       out_data[i] = true;
     }
-    bool val;
+    bool val = false;
     int res_index = -1;
     for (int i = 0; i < num; i++) {
       const phi::dtype::complex<T> a = in_a[i], b = in_b[i];

paddle/phi/kernels/impl/einsum_grad_kernel_impl.h

@@ -44,7 +44,7 @@ DenseTensor PerformTileAndReduction(const Context& dev_ctx,
   std::vector<int64_t> resize_dims;
   std::vector<int64_t> recover_shape;
   std::vector<int64_t> t_shape = common::vectorize<int64_t>(t.dims());
-  for (int i = 0; i < op_label.size(); i++) {
+  for (size_t i = 0; i < op_label.size(); i++) {
     int c = op_label[i];
     if (label2type[c] == LabelType::Reduction) {
       repeat_times.push_back(label2shape[c]);
@@ -64,7 +64,7 @@ DenseTensor PerformTileAndReduction(const Context& dev_ctx,
                         "shape size: `%d`, but got label nums: `%d`",
                         t_shape.size(),
                         op_label.size()));
-  for (int i = 0; i < op_label.size(); i++) {
+  for (size_t i = 0; i < op_label.size(); i++) {
     int c = op_label[i];
     if (label2type[c] == LabelType::Contraction &&
         t_shape[i] != label2shape[c]) {