pgsql: pg_upgrade: Make test.sh's installcheck use to-be-upgradedversi

pg_upgrade: Make test.sh's installcheck use to-be-upgraded version's bindir.

On master (after 700538) the old version's installed psql was used -
even when the old version might not actually be installed / might be
installed into a temporary directory. As commonly the case when just
executing make check for pg_upgrade, as $oldbindir is just the current
version's $bindir.

In the back branches, with --install specified, psql from the new
version's temporary installation was used, without --install (e.g for
NO_TEMP_INSTALL, cf 47b3c26642), the new version's installed psql was
used (which might or might not exist).

Author: Andres Freund
Discussion: https://postgr.es/m/20190522175150.c26f4jkqytahajdg@alap3.anarazel.de

Branch
------
REL_11_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/5d91a9e8ac9cc6dc9d3695fcaa41132f2c4f0a89

Modified Files
--------------
src/bin/pg_upgrade/test.sh | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)