!6609 [MD] fix mindrecord log

Merge pull request !6609 from liyong126/fix_mindrecord_log

mindspore/ccsrc/minddata/mindrecord/meta/shard_header.cc

@@ -118,7 +118,7 @@ std::pair<MSRStatus, json> ShardHeader::ValidateHeader(const std::string &path)
 
   if (header_size > kMaxHeaderSize) {
     fin.close();
-    MS_LOG(ERROR) << "Invalid file. path: " << path;
+    MS_LOG(ERROR) << "Invalid file content. path: " << path;
     return {FAILED, json_header};
   }