Use ereport() rather than elog()

Noah pointed this out before I committed 50f770c3d9, but I
accidentally pushed the old version with elog() anyway. Oops.

Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://www.postgresql.org/message-id/20250820003756.31.nmisch@google.com

src/backend/access/heap/heapam.c

@@ -1148,8 +1148,10 @@ heap_beginscan(Relation relation, Snapshot snapshot,
 		IsHistoricMVCCSnapshot(snapshot) &&
 		!RelationIsAccessibleInLogicalDecoding(relation))
 	{
-		elog(ERROR, "cannot query non-catalog table \"%s\" during logical decoding",
-			 RelationGetRelationName(relation));
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
+				 errmsg("cannot query non-catalog table \"%s\" during logical decoding",
+						RelationGetRelationName(relation))));
 	}
 
 	/*

src/backend/access/index/indexam.c

@@ -267,8 +267,10 @@ index_beginscan(Relation heapRelation,
 	if (IsHistoricMVCCSnapshot(snapshot) &&
 		!RelationIsAccessibleInLogicalDecoding(heapRelation))
 	{
-		elog(ERROR, "cannot query non-catalog table \"%s\" during logical decoding",
-			 RelationGetRelationName(heapRelation));
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
+				 errmsg("cannot query non-catalog table \"%s\" during logical decoding",
+						RelationGetRelationName(heapRelation))));
 	}
 
 	scan = index_beginscan_internal(indexRelation, nkeys, norderbys, snapshot, NULL, false);