pgsql: Add ORDER BY to a query to prevent occasional regression test fa

Add ORDER BY to a query to prevent occasional regression test failures.

Per buildfarm, we sometimes get row-ordering variations in the output.
This also makes this query look more like numerous other ones in the same
test file.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/d06e2d200562837afa18058937f20460a3ea526a

Modified Files
--------------
src/test/regress/expected/inherit.out | 2 +-
src/test/regress/sql/inherit.sql | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)