Appease perlcritic

Food for the gods must always be found somehow, even when the land starves.

src/test/recovery/t/019_replslot_limit.pl

@@ -192,6 +192,7 @@ sub advance_wal
 	{
 		$node->safe_psql('postgres', "CREATE TABLE t (); DROP TABLE t; SELECT pg_switch_wal();");
 	}
+	return;
 }
 
 # return the size of logfile of $node in bytes