pgsql: Return proper value for psql -f filename failure if filename open

Log Message:
-----------
Return proper value for psql -f filename failure if filename open fails.

Backpatch to 8.0.X.

Tags:
----
REL8_0_STABLE

Modified Files:
--------------
pgsql/src/bin/psql:
command.c (r1.139 -> r1.139.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/command.c.diff?r1=1.139&r2=1.139.4.1)
startup.c (r1.112 -> r1.112.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/startup.c.diff?r1=1.112&r2=1.112.4.1)