core: reduce nesting in transaction pool code (#16980)

core/tx_pool.go

@@ -815,13 +815,11 @@ func (pool *TxPool) addTxsLocked(txs []*types.Transaction, local bool) []error {
 
 	for i, tx := range txs {
 		var replace bool
-		if replace, errs[i] = pool.add(tx, local); errs[i] == nil {
-			if !replace {
+		if replace, errs[i] = pool.add(tx, local); errs[i] == nil && !replace {
 			from, _ := types.Sender(pool.signer, tx) // already validated
 			dirty[from] = struct{}{}
 		}
 	}
-	}
 	// Only reprocess the internal state if something was actually added
 	if len(dirty) > 0 {
 		addrs := make([]common.Address, 0, len(dirty))