pgsql: Fix object identity string for transforms

Fix object identity string for transforms

In commit ad89a5d115b3, 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

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/9a312562314abcec91ae9cff3a4af37196c3886e

Modified Files
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src/backend/catalog/objectaddress.c          | 2 +-
src/test/regress/expected/object_address.out | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)