pgsql: Fix wrong allocation size in c8f621c43.

pgsql: Fix wrong allocation size in c8f621c43.

Fix wrong allocation size in c8f621c43.

In c8f621c43 I forgot to account for MAXALIGN when allocating a new
tuplebuf in ReorderBufferGetTupleBuf(). That happens to currently not
cause active problems on a number of platforms because the affected
pointer is already aligned, but others, like ppc and hppa, trigger this
in the regression test, due to a debug memset clearing memory.

Fix that.

Backpatch: 9.4, like the previous commit.

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/fb3ea0465c1710c565e98d4b3e37aebb4e487eaf

Modified Files
--------------
src/backend/replication/logical/reorderbuffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)