pgsql: Correct the formulas for System V IPC parameters SEMMNI and SEMM

Correct the formulas for System V IPC parameters SEMMNI and SEMMNS in docs.

In runtime.sgml, the old formulas for calculating the reasonable
values of SEMMNI and SEMMNS were incorrect. They have forgotten to
count the number of semaphores which both the checkpointer process
(introduced in 9.2) and the background worker processes (introduced
in 9.3) need.

This commit fixes those formulas so that they count the number of
semaphores which the checkpointer process and the background worker
processes need.

Report and patch by Kyotaro Horiguchi. Only the patch for 9.3 was
modified by me. Back-patch to 9.2 where the checkpointer process was
added and the number of needed semaphores was increased.

Author: Kyotaro Horiguchi
Reviewed-by: Fujii Masao
Backpatch: 9.2
Discussion: http://www.postgresql.org/message-id/20160203.125119.66820697.horiguchi.kyotaro@lab.ntt.co.jp

Branch
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REL9_3_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/984da963fb450252eb444402a30c7dd0b54e1c69

Modified Files
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doc/src/sgml/runtime.sgml | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)