MDEV-28301 Spider: Fix GCC warnings, comparing the result of pointer addition ... and NULL

The condition of the if statements are always true.

Author: nayuta-yanagisawa

storage/spider/spd_db_mysql.cc

@@ -3444,27 +3444,15 @@ int spider_db_mbase::append_lock_tables(
  conn_link_idx = tmp_spider->conn_link_idx[tmp_link_idx];
  spider_mbase_share *db_share = (spider_mbase_share *)
  tmp_spider->share->dbton_share[conn->dbton_id];
- if (&db_share->db_names_str[conn_link_idx])
- {
- db_name = db_share->db_names_str[conn_link_idx].ptr();
- db_name_length = db_share->db_names_str[conn_link_idx].length();
- db_name_charset = tmp_spider->share->access_charset;
- } else {
- db_name = tmp_spider->share->tgt_dbs[conn_link_idx];
- db_name_length = tmp_spider->share->tgt_dbs_lengths[conn_link_idx];
- db_name_charset = system_charset_info;
- }
- if (&db_share->table_names_str[conn_link_idx])
- {
- table_name = db_share->table_names_str[conn_link_idx].ptr();
- table_name_length = db_share->table_names_str[conn_link_idx].length();
- table_name_charset = tmp_spider->share->access_charset;
- } else {
- table_name = tmp_spider->share->tgt_table_names[conn_link_idx];
- table_name_length =
- tmp_spider->share->tgt_table_names_lengths[conn_link_idx];
- table_name_charset = system_charset_info;
- }
+
+ db_name = db_share->db_names_str[conn_link_idx].ptr();
+ db_name_length = db_share->db_names_str[conn_link_idx].length();
+ db_name_charset = tmp_spider->share->access_charset;
+
+ table_name = db_share->table_names_str[conn_link_idx].ptr();
+ table_name_length = db_share->table_names_str[conn_link_idx].length();
+ table_name_charset = tmp_spider->share->access_charset;
+
  if ((error_num = spider_db_mbase_utility->
  append_lock_table_body(
  str,