pgsql: doc: simplify wording of function error affects

doc: simplify wording of function error affects

Reported-by: bob.henkel@gmail.com

Discussion: /messages/by-id/160324449781.693.8298142858847611071@wrigleys.postgresql.org

Backpatch-through: 9.5

Branch
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REL9_5_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/98529445a360144f71092a9377cb5fc3e2d634e2

Modified Files
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doc/src/sgml/plpgsql.sgml | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)