pgsql: Fix memory leak for file name if expect file name contains a dot,

Log Message:
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Fix memory leak for file name if expect file name contains a dot, per
report from dvice_null@yahoo.com.

Modified Files:
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pgsql/src/test/regress:
pg_regress.c (r1.56 -> r1.57)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/pg_regress.c?r1=1.56&r2=1.57)