pgsql: Silence unused variable compiler warning

Silence unused variable compiler warning

Fallout from fcec6caafa2: mark a variable in
set_tablefunc_size_estimates as used for asserts only.

Also, the planner_rte_fetch() call is pointless with assertions
disabled, so enclose it in a USE_ASSERT_CHECKING #ifdef; fix the same
problem in set_subquery_size_estimates().

First problem noted by David Rowley, whose compiler is noisier than mine
in this regard.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/a9c074ba7ec2827832c2f5e2fa0de16bf4851b9b

Modified Files
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src/backend/optimizer/path/costsize.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)