pgsql: Fix possible failure to mark hash metapage dirty.

Fix possible failure to mark hash metapage dirty.

Report and suggested fix by Lixian Zou. Amit Kapila put it
in the form of a patch and reviewed.

Discussion: http://postgr.es/m/[email protected]

Branch
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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/b94988fad56167915231d3d2b275c471914301fe

Modified Files
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src/backend/access/hash/hashovfl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)