Fixed results for NULL and NaN distances [skip ci]

test/expected/hnsw_ip.out

@@ -13,8 +13,12 @@ SELECT * FROM t ORDER BY val <#> '[3,3,3]';
 (4 rows)
 
 SELECT * FROM t ORDER BY val <#> (SELECT NULL::vector);
- val 
------
-(0 rows)
+   val   
+---------
+ [1,1,1]
+ [1,2,4]
+ [1,2,3]
+ [0,0,0]
+(4 rows)
 
 DROP TABLE t;