pgsql: Fix sloppy cleanup of roles in privileges.sql.

Fix sloppy cleanup of roles in privileges.sql.

Commit 3d14e171e dropped regress_roleoption_donor twice and
regress_roleoption_protagonist not at all.  Leaving roles behind
after "make installcheck" is unfriendly in its own right, plus
it causes repeated runs of "make installcheck" to fail.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/b62303794efd97f2afb55f1e1b82fffae2cf8a2d

Modified Files
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src/test/regress/expected/privileges.out | 5 ++---
src/test/regress/sql/privileges.sql      | 4 ++--
2 files changed, 4 insertions(+), 5 deletions(-)