Fix typo

Author: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>

Author: petere

src/backend/executor/execMain.c

@@ -3334,7 +3334,7 @@ ExecFindPartition(ResultRelInfo *resultRelInfo, PartitionDispatch *pd,
 
 	/*
 	 * First check the root table's partition constraint, if any.  No point in
-	 * routing the tuple it if it doesn't belong in the root table itself.
+	 * routing the tuple if it doesn't belong in the root table itself.
 	 */
 	if (resultRelInfo->ri_PartitionCheck)
 		ExecPartitionCheck(resultRelInfo, slot, estate);