pgsql: Fix bug in generation.c's valgrind support.

Fix bug in generation.c's valgrind support.

This doesn't look like the last such bug, but it's one that the
test_decoding regression test is tripping over.  Per buildfarm.

Tomas Vondra

Discussion: https://postgr.es/m/c903f275-2150-fa52-64bf-dca7b53ebf8d@fuzzy.cz

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/cc3c4af4a948e5c5be22afe769bab41235c574e5

Modified Files
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src/backend/utils/mmgr/generation.c | 5 +++++
1 file changed, 5 insertions(+)