Fix ndberror after jonas comments

ndb/include/ndbapi/NdbError.hpp

@@ -206,7 +206,7 @@ struct NdbError {
     message = 0;
     details = 0;
   }
-  NdbError(ndberror_struct ndberror){
+  NdbError(const ndberror_struct & ndberror){
     status = (NdbError::Status) ndberror.status;
     classification = (NdbError::Classification) ndberror.classification;
     code = ndberror.code;

ndb/include/ndbapi/ndberror.h

@@ -88,8 +88,8 @@ typedef struct {
 typedef ndberror_status_enum ndberror_status;
 typedef  ndberror_classification_enum ndberror_classification;
 
-const char *ndberror_status_message(const ndberror_status);
-const char *ndberror_classification_message(const ndberror_classification);
+const char *ndberror_status_message(ndberror_status);
+const char *ndberror_classification_message(ndberror_classification);
 void ndberror_update(ndberror_struct *);
 int ndb_error_string(int err_no, char *str, size_t size);