Fix object identity string for transforms

In commit ad89a5d, we added an unhelpful 'ON' that doesn't match
the input syntax.  This was discovered while adding code to support for
DDL in logical replication.

No backpatch because of the change of behavior, however improbable it
may be that somebody is depending on this.

Author: Zheng Li <zhengli10@gmail.com>
Discussion: https://postgr.es/m/CAAD30UKg8rXeGM8Oy_MAmxKBL_K5DiHXdeNF=hUefcu1C_6VfQ@mail.gmail.com

Author: alvherre

src/backend/catalog/objectaddress.c

@@ -5922,7 +5922,7 @@ getObjectIdentityParts(const ObjectAddress *object,
 				transformType = format_type_be_qualified(transform->trftype);
 				transformLang = get_language_name(transform->trflang, false);
 
-				appendStringInfo(&buffer, "for %s on language %s",
+				appendStringInfo(&buffer, "for %s language %s",
 								 transformType,
 								 transformLang);
 				if (objname)

src/test/regress/expected/object_address.out

@@ -496,7 +496,7 @@ operator family|pg_catalog|integer_ops|pg_catalog.integer_ops USING btree|t
 policy|NULL|NULL|genpol on addr_nsp.gentable|t
 statistics object|addr_nsp|gentable_stat|addr_nsp.gentable_stat|t
 collation|pg_catalog|"default"|pg_catalog."default"|t
-transform|NULL|NULL|for integer on language sql|t
+transform|NULL|NULL|for integer language sql|t
 text search dictionary|addr_nsp|addr_ts_dict|addr_nsp.addr_ts_dict|t
 text search parser|addr_nsp|addr_ts_prs|addr_nsp.addr_ts_prs|t
 text search configuration|addr_nsp|addr_ts_conf|addr_nsp.addr_ts_conf|t