[MD] code review

mindspore/ccsrc/minddata/dataset/engine/ir/datasetops/source/minddata_node.cc

@@ -70,9 +70,9 @@ Status MindDataNode::ValidateParams() {
   }
 
   if (padded_sample_ != nullptr) {
-    if (num_padded_ < 0) {
+    if (num_padded_ < 0 || num_padded_ > INT_MAX) {
       std::string err_msg =
-        "MindDataNode: num_padded must be greater than or equal to zero, num_padded: " + std::to_string(num_padded_);
+        "MindDataNode: num_padded must to be between 0 and INT32_MAX, but got: " + std::to_string(num_padded_);
       MS_LOG(ERROR) << err_msg;
       RETURN_STATUS_SYNTAX_ERROR(err_msg);
     }

mindspore/dataset/vision/c_transforms.py

@@ -560,7 +560,7 @@ class RandomPosterize(cde.RandomPosterizeOp):
             Bits values must be in range of [1,8], and include at
             least one integer value in the given range. It must be in
             (min, max) or integer format. If min=max, then it is a single fixed
-            magnitude operation (default=[4, 8]).
+            magnitude operation (default=[8, 8]).
 
     Examples:
         >>> import mindspore.dataset.vision.c_transforms as c_vision