pgsql: Simplify EXPLAIN code for Memoize

Simplify EXPLAIN code for Memoize

This removes a needless special case for Memoize's FORMAT TEXT EXPLAIN
output.

ExplainPropertyText() outputs the same thing in text mode as the
special-case code was doing, so removing the special-case code results in
the same EXPLAIN output, just with less code.

It seems like a good idea to fix this to help prevent future changes in
this area from copying the same pattern.

Author: Ilia Evdokimov <ilya(dot)evdokimov(at)tantorlabs(dot)com>
Reported-by: David Rowley <dgrowleyml(at)gmail(dot)com>
Discussion: https://postgr.es/m/88a71bcd-0b5c-4d0b-8107-757e96f402d5@tantorlabs.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/00b52c3db66c5ec2593463c43371525deff95347

Modified Files
--------------
src/backend/commands/explain.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)