Fix compiler warning.
Fix compiler warning.

Kevin Gritter reports that his compiler complains about inq and outq
being possibly-uninitialized at the point where they are passed to
shm_mq_attach().  They are initialized by the call to
setup_dynamic_shared_memory, but apparently his compiler is inlining
that function and then having doubts about whether the for loop will
always execute at least once.  Fix by initializing them to NULL.

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