pgstattuple: Fix typo partitiond -> partitioned

Pointed out by Michael Paquier

contrib/pgstattuple/expected/pgstattuple.out

@@ -223,7 +223,7 @@ select pgstatginindex('test_partition');
 ERROR:  relation "test_partition" is not a GIN index
 select pgstathashindex('test_partition');
 ERROR:  "test_partition" is not an index
+-- an actual index of a partitioned table should work though
 create index test_partition_idx on test_partition(a);
 create index test_partition_hash_idx on test_partition using hash (a);
 WARNING:  hash indexes are not WAL-logged and their use is discouraged

contrib/pgstattuple/sql/pgstattuple.sql

@@ -103,7 +103,7 @@ select pgstatindex('test_partition');
 select pgstatginindex('test_partition');
 select pgstathashindex('test_partition');
 
+-- an actual index of a partitioned table should work though
 create index test_partition_idx on test_partition(a);
 create index test_partition_hash_idx on test_partition using hash (a);
 -- these should work