pgsql: Fix variable confusion in BufferSync().

Fix variable confusion in BufferSync().

As noted by Heikki Linnakangas, the previous coding confused the "flags"
variable with the "mask" variable. The affect of this appears to be that
unlogged buffers would get written out at every checkpoint rather than
only at shutdown time. Although that's arguably an acceptable failure
mode, I'm back-patching this change, since it seems like a poor idea to
rely on this happening to work.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/f9f04845045086feb1144f52cc2911e9f08efe3f

Modified Files
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src/backend/storage/buffer/bufmgr.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)