Fix oversight in commit 4429f6a9.

The test name and the following test cases suggest the index created
should be hash index, but it forgot to add 'using hash' in the test case.
This in itself won't improve code coverage as there were some other tests
which were covering the corresponding code.  However, it is better if the
added tests serve their actual purpose.

Reported-by: Paul A Jungwirth
Author: Paul A Jungwirth
Reviewed-by: Mahendra Singh
Backpatch-through: 9.4
Discussion: https://postgr.es/m/CA+renyV=Us-5XfMC25bNp-uWSj39XgHHmGE9Rh2cQKMegSj52g@mail.gmail.com

src/test/regress/expected/rangetypes.out

@@ -519,7 +519,7 @@ select numrange(1.0, 2.0) * numrange(2.5, 3.0);
 (1 row)
 
 create table numrange_test2(nr numrange);
-create index numrange_test2_hash_idx on numrange_test2 (nr);
+create index numrange_test2_hash_idx on numrange_test2 using hash (nr);
 INSERT INTO numrange_test2 VALUES('[, 5)');
 INSERT INTO numrange_test2 VALUES(numrange(1.1, 2.2));
 INSERT INTO numrange_test2 VALUES(numrange(1.1, 2.2));

src/test/regress/sql/rangetypes.sql

@@ -119,7 +119,7 @@ select numrange(1.0, 2.0) * numrange(1.5, 3.0);
 select numrange(1.0, 2.0) * numrange(2.5, 3.0);
 
 create table numrange_test2(nr numrange);
-create index numrange_test2_hash_idx on numrange_test2 (nr);
+create index numrange_test2_hash_idx on numrange_test2 using hash (nr);
 
 INSERT INTO numrange_test2 VALUES('[, 5)');
 INSERT INTO numrange_test2 VALUES(numrange(1.1, 2.2));