pgsql: Adjustments to regression tests for security_barrier views.

Adjustments to regression tests for security_barrier views.

Drop the role we create, so regression tests pass even when run more
than once against the same cluster, a problem noted by Tom Lane and
Jeff Janes. Also, rename the temporary role so that it starts with
"regress_", to make it unlikely that we'll collide with an existing
role name while running "make installcheck", per further gripe from
Tom Lane.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/49562f5eb66f31940dd7b64555bbd81bae952387

Modified Files
--------------
src/test/regress/expected/select_views.out | 83 +++++++++++++------------
src/test/regress/expected/select_views_1.out | 83 +++++++++++++------------
src/test/regress/sql/select_views.sql | 16 +++--
3 files changed, 96 insertions(+), 86 deletions(-)