Make LOCK_PRINT & PROCLOCK_PRINT expand to ((void) 0) when not in use.
Make LOCK_PRINT & PROCLOCK_PRINT expand to ((void) 0) when not in use.

This avoids warnings from more-anal-than-average compilers, and might
prevent hidden syntax problems in the future.

Andres Freund

xinzweb/gpdb,greenplum-db/gpdb,50wu/gpdb,lisakowen/gpdb,lisakowen/gpdb,adam8157/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,lisakowen/gpdb,zeroae/postgres-xl,Postgres-XL/Postgres-XL,lisakowen/gpdb,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,xinzweb/gpdb,zeroae/postgres-xl,yazun/postgres-xl,jmcatamney/gpdb,yazun/postgres-xl,greenplum-db/gpdb,xinzweb/gpdb,lisakowen/gpdb,jmcatamney/gpdb,xinzweb/gpdb,zeroae/postgres-xl,lisakowen/gpdb,50wu/gpdb,oberstet/postgres-xl,xinzweb/gpdb,ashwinstar/gpdb,ovr/postgres-xl,lisakowen/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,ovr/postgres-xl,jmcatamney/gpdb,50wu/gpdb,oberstet/postgres-xl,adam8157/gpdb,jmcatamney/gpdb,Postgres-XL/Postgres-XL,jmcatamney/gpdb,ovr/postgres-xl,techdragon/Postgres-XL,pavanvd/postgres-xl,ashwinstar/gpdb,xinzweb/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,pavanvd/postgres-xl,jmcatamney/gpdb,oberstet/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,50wu/gpdb,yazun/postgres-xl,lisakowen/gpdb,jmcatamney/gpdb,adam8157/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,ashwinstar/gpdb,50wu/gpdb,oberstet/postgres-xl,oberstet/postgres-xl,techdragon/Postgres-XL,ovr/postgres-xl,adam8157/gpdb,adam8157/gpdb,ashwinstar/gpdb,yazun/postgres-xl,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,xinzweb/gpdb,yazun/postgres-xl,adam8157/gpdb,50wu/gpdb,zeroae/postgres-xl,50wu/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,ovr/postgres-xl,pavanvd/postgres-xl,adam8157/gpdb,50wu/gpdb,techdragon/Postgres-XL,zeroae/postgres-xl