pgsql: Fix broken example in PL/pgSQL document.

Fix broken example in PL/pgSQL document.

Back-patch to all supported branches.

Marti Raudsepp, per a report from Marko Tiikkaja

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/a0c58b55220f190e8be9cfe0cadb4d478e13fac2

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