pgsql: Fix Xmax freeze conditions

Fix Xmax freeze conditions

I broke this in 0ac5ad5134; previously, freezing a tuple marked with an
IS_MULTI xmax was not necessary.

Per brokenness report from Jeff Janes.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/5766228bc64268369b59b07cffa7d31cd4f9c9ff

Modified Files
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src/backend/access/heap/heapam.c |    9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)