pg_amcheck: PQclear query results
While the potential memory leak is small, ensure to PQclear the query
results before disconnecting.
Author: Jiao Shuntian <
312199339@qq.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/tencent_F34922C91C41E76C734773E767C9FBDB9906@qq.com