core/txpool: no need to run rotate if no local txs

Signed-off-by: jsvisa <delweng@gmail.com>

core/txpool/legacypool/journal.go

@@ -131,6 +131,11 @@ func (journal *journal) insert(tx *types.Transaction) error {
 // rotate regenerates the transaction journal based on the current contents of
 // the transaction pool.
 func (journal *journal) rotate(all map[common.Address]types.Transactions) error {
+	// No need to rotate if there are no transactions to write
+	if len(all) == 0 {
+		return nil
+	}
+
 	// Close the current journal (if any is open)
 	if journal.writer != nil {
 		if err := journal.writer.Close(); err != nil {