pgsql: Properly acquire buffer lock for page-at-a-time hash vacuum.

Properly acquire buffer lock for page-at-a-time hash vacuum.

In a couple of places, _hash_kill_items was mistakenly called with
the buffer lock not held.  Repair.

Ashutosh Sharma, per a report from Andreas Seltenreich

Discussion: http://postgr.es/m/87o9wo8o0j.fsf@credativ.de

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/93cd7684ee2bba227fa371daa81b88f25456dcb2

Modified Files
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src/backend/access/hash/hash.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)