gas-oracle: fix linting errors

go/gas-oracle/oracle/base_fee.go

@@ -42,6 +42,9 @@ func wrapUpdateBaseFee(l1Backend bind.ContractTransactor, l2Backend DeployContra
 		baseFee, err := contract.L1BaseFee(&bind.CallOpts{
 			Context: context.Background(),
 		})
+		if err != nil {
+			return err
+		}
 		tip, err := l1Backend.HeaderByNumber(context.Background(), nil)
 		if err != nil {
 			return err

go/gas-oracle/oracle/gas_price_oracle.go

@@ -315,10 +315,10 @@ func ensureConnection(client *ethclient.Client) error {
 	for ; true; <-t.C {
 		_, err := client.ChainID(context.Background())
 		if err == nil {
-			t.Stop()
 			break
+		} else {
+			return err
 		}
-		return err
 	}
 	return nil
 }