BUG #15838: [contrib] vacuumlo: schema variable checked for NULL three times

The following bug has been logged on the website:

Bug reference:      15838
Logged by:          Timur Birsh
Email address:      taem@linukz.org
PostgreSQL version: 11.2
Operating system:   CentOS 7
Description:

Hello,

vacuumlo() has this (starting on line 239):

                if (!schema || !table || !field)
                {
                        fprintf(stderr, "%s", PQerrorMessage(conn));
                        PQclear(res);
                        PQfinish(conn);
                        if (schema != NULL)
                                PQfreemem(schema);
                        if (schema != NULL)
                                PQfreemem(table);
                        if (schema != NULL)
                                PQfreemem(field);
                        return -1;
                }

I think this can be replaced with this:

                if (!schema || !table || !field)
                {
                        fprintf(stderr, "%s", PQerrorMessage(conn));
                        PQclear(res);
                        PQfinish(conn);
                        if (schema != NULL) {
                                PQfreemem(schema);
                                PQfreemem(table);
                                PQfreemem(field);
                        }
                        return -1;
                }

Thanks,
Timur