Update core/txpool/txpool.go

Co-authored-by: jwasinger <[email protected]>

Author: dahu33

core/txpool/txpool.go

@@ -486,6 +486,8 @@ func (p *TxPool) Sync() error {
 
 // Clear removes all tracked txs from the subpools.
 func (p *TxPool) Clear() {
+	// Invoke Sync to ensure that txs pending addition don't get added to the pool after
+	// the subpools are subsequently cleared
 	p.Sync()
 	for _, subpool := range p.subpools {
 		subpool.Clear()