Fix comment in regression tests for large objects

The values assigned to INV_WRITE and INV_READ were reversed in the
tests, which would be confusing when writing tests specific to read or
write operations on LOs.

Author: Yugo Nagata
Discussion: https://postgr.es/m/20220527153028.61a4608f66abcd026fd3806f@sraoss.co.jp

Author: michaelpq

src/test/regress/expected/largeobject.out

@@ -50,8 +50,8 @@ INSERT INTO lotest_stash_values (loid) SELECT lo_creat(42);
 BEGIN;
 -- lo_open(lobjId oid, mode integer) returns integer
 -- The mode parameter to lo_open uses two constants:
---   INV_READ  = 0x20000
---   INV_WRITE = 0x40000
+--   INV_WRITE = 0x20000
+--   INV_READ  = 0x40000
 -- The return value is a file descriptor-like value which remains valid for the
 -- transaction.
 UPDATE lotest_stash_values SET fd = lo_open(loid, CAST(x'20000' | x'40000' AS integer));

src/test/regress/expected/largeobject_1.out

@@ -50,8 +50,8 @@ INSERT INTO lotest_stash_values (loid) SELECT lo_creat(42);
 BEGIN;
 -- lo_open(lobjId oid, mode integer) returns integer
 -- The mode parameter to lo_open uses two constants:
---   INV_READ  = 0x20000
---   INV_WRITE = 0x40000
+--   INV_WRITE = 0x20000
+--   INV_READ  = 0x40000
 -- The return value is a file descriptor-like value which remains valid for the
 -- transaction.
 UPDATE lotest_stash_values SET fd = lo_open(loid, CAST(x'20000' | x'40000' AS integer));

src/test/regress/sql/largeobject.sql

@@ -34,8 +34,8 @@ BEGIN;
 
 -- lo_open(lobjId oid, mode integer) returns integer
 -- The mode parameter to lo_open uses two constants:
---   INV_READ  = 0x20000
---   INV_WRITE = 0x40000
+--   INV_WRITE = 0x20000
+--   INV_READ  = 0x40000
 -- The return value is a file descriptor-like value which remains valid for the
 -- transaction.
 UPDATE lotest_stash_values SET fd = lo_open(loid, CAST(x'20000' | x'40000' AS integer));