Remove repeated test in contrib/amcheck

Repeating these tests adds unnecessary cycles, since no improvement in
test coverage is expected.

Cleanup from commit 8224de4f.

Peter Geoghegan

contrib/amcheck/expected/check_btree.out

@@ -111,27 +111,9 @@ SELECT bt_index_parent_check('bttest_multi_idx', true);
  
 (1 row)
 
-SELECT bt_index_parent_check('bttest_multi_idx', true);
- bt_index_parent_check 
------------------------
- 
-(1 row)
-
--- repeat same checks with index made by insertions
+-- repeat expansive test for index built using insertions
 TRUNCATE bttest_multi;
 INSERT INTO bttest_multi SELECT i, i%2  FROM generate_series(1, 100000) as i;
-SELECT bt_index_check('bttest_multi_idx');
- bt_index_check 
-----------------
- 
-(1 row)
-
-SELECT bt_index_parent_check('bttest_multi_idx', true);
- bt_index_parent_check 
------------------------
- 
-(1 row)
-
 SELECT bt_index_parent_check('bttest_multi_idx', true);
  bt_index_parent_check 
 -----------------------

contrib/amcheck/sql/check_btree.sql

@@ -65,15 +65,11 @@ COMMIT;
 SELECT bt_index_check('bttest_multi_idx');
 -- more expansive test for index with included columns
 SELECT bt_index_parent_check('bttest_multi_idx', true);
-SELECT bt_index_parent_check('bttest_multi_idx', true);
 
--- repeat same checks with index made by insertions
+-- repeat expansive test for index built using insertions
 TRUNCATE bttest_multi;
 INSERT INTO bttest_multi SELECT i, i%2  FROM generate_series(1, 100000) as i;
-SELECT bt_index_check('bttest_multi_idx');
 SELECT bt_index_parent_check('bttest_multi_idx', true);
-SELECT bt_index_parent_check('bttest_multi_idx', true);
-
 
 -- cleanup
 DROP TABLE bttest_a;