MDEV-34388 Alpine Stack Overflow - reduce Grant_tables::open_and_lock

The stacksize was still too large. Back port from the 10.11 merge
commit 1c7209e828

sql/sql_acl.cc

@@ -2012,13 +2012,25 @@ class Grant_tables
   {
     DBUG_ENTER("Grant_tables::open_and_lock");
 
-    TABLE_LIST tables[USER_TABLE+1], *first= NULL;
+    TABLE_LIST *first= nullptr, *tables=
+      static_cast<TABLE_LIST*>(my_malloc(PSI_NOT_INSTRUMENTED,
+                                         (USER_TABLE + 1) * sizeof *tables,
+                                         MYF(MY_WME)));
+    int res= -1;
+
+    if (!tables)
+    {
+    func_exit:
+      my_free(tables);
+      DBUG_RETURN(res);
+    }
+
 
     if (build_table_list(thd, &first, which_tables, lock_type, tables))
-      DBUG_RETURN(-1);
+      goto func_exit;
 
     uint counter;
-    int res= really_open(thd, first, &counter);
+    res= really_open(thd, first, &counter);
 
     /* if User_table_json wasn't found, let's try User_table_tabular */
     if (!res && (which_tables & Table_user) && !tables[USER_TABLE].table)
@@ -2044,12 +2056,15 @@ class Grant_tables
       }
     }
     if (res)
-      DBUG_RETURN(res);
+      goto func_exit;
 
     if (lock_tables(thd, first, counter,
                     MYSQL_LOCK_IGNORE_TIMEOUT |
                     MYSQL_OPEN_IGNORE_LOGGING_FORMAT))
-      DBUG_RETURN(-1);
+    {
+      res= -1;
+      goto func_exit;
+    }
 
     p_user_table->set_table(tables[USER_TABLE].table);
     m_db_table.set_table(tables[DB_TABLE].table);
@@ -2059,7 +2074,7 @@ class Grant_tables
     m_procs_priv_table.set_table(tables[PROCS_PRIV_TABLE].table);
     m_proxies_priv_table.set_table(tables[PROXIES_PRIV_TABLE].table);
     m_roles_mapping_table.set_table(tables[ROLES_MAPPING_TABLE].table);
-    DBUG_RETURN(0);
+    goto func_exit;
   }
 
   inline const User_table& user_table() const