Log Message:
-----------
Make checks for invalid pgStatSock use PGINVALID_SOCKET
Modified Files:
--------------
pgsql/src/backend/postmaster:
pgstat.c (r1.199 -> r1.200)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/pgstat.c?r1=1.199&r2=1.200)