pgsql: Fix ancient memory leak in PQprintTuples(); our code no longer

Log Message:
-----------
Fix ancient memory leak in PQprintTuples(); our code no longer uses this
routine, but perhaps some applications do. Found by Martijn van Oosterhout
using Coverity.

Modified Files:
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pgsql/src/interfaces/libpq:
fe-print.c (r1.67 -> r1.68)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-print.c.diff?r1=1.67&r2=1.68)