This leak is not important, since "ovsdb-tool create" is a short-running
command, but we might as well fix it.
Found with valgrind.
/* Read schema from file and convert to JSON. */
check_ovsdb_error(ovsdb_schema_from_file(schema_file_name, &schema));
json = ovsdb_schema_to_json(schema);
+ ovsdb_schema_destroy(schema);
/* Create database file. */
check_ovsdb_error(ovsdb_log_open(db_file_name, O_RDWR | O_CREAT | O_EXCL,