Remove surplus call to table_finish_bulk_insert

4de60244e added the call to table_finish_bulk_insert to the
CopyMultiInsertBufferCleanup function.  We use a CopyMultiInsertBuffer even
for non-partitioned tables, so having the cleanup do that meant we would
call table_finsh_bulk_insert twice when performing COPY FROM with
a non-partitioned table.

Here we can just remove the direct call in CopyFrom and let
CopyMultiInsertBufferCleanup handle the call instead.

src/backend/commands/copy.c

@@ -3369,8 +3369,6 @@ CopyFrom(CopyState cstate)
 
 	if (insertMethod != CIM_SINGLE)
 	{
-		table_finish_bulk_insert(cstate->rel, ti_options);
-
 		/* Tear down the multi-insert buffer data */
 		CopyMultiInsertInfoCleanup(&multiInsertInfo);
 	}