pgsql: Fix unportable (and incorrect anyway) usage of LL constant suffix

Log Message:
-----------
Fix unportable (and incorrect anyway) usage of LL constant suffix that
recently snuck into cash.c. Per report from Edmundo Robles Lopez.

Modified Files:
--------------
pgsql/src/backend/utils/adt:
cash.c (r1.79 -> r1.80)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/cash.c?r1=1.79&r2=1.80)