A cleanup for MDEV-12668 SRID is not preserved in UNION, VIEW, MIN, MAX

Fixing storage/mroonga according to MDEV-12668

storage/mroonga/ha_mroonga.cpp

@@ -11895,7 +11895,7 @@ int ha_mroonga::storage_encode_key_set(Field *field, const uchar *key,
                      field->null_bit, field->unireg_check,
                      &field->field_name,
                      field->pack_length(),
-                     static_cast<Field_set*>(field)->typelib,
+                     static_cast<Field_set*>(field)->typelib(),
                      static_cast<Field_set*>(field)->charset());
   switch (field->pack_length()) {
   case 1:

storage/mroonga/lib/mrn_condition_converter.cpp

@@ -599,7 +599,7 @@ namespace mrn {
           string = const_item->val_str(NULL);
           Field_enum *enum_field = static_cast<Field_enum *>(field_item->field);
           int enum_value = find_type(string->c_ptr(),
-                                     enum_field->typelib,
+                                     enum_field->typelib(),
                                      FIND_TYPE_BASIC);
           GRN_INT64_SET(ctx_, &value_, enum_value);
         } else {