update comment

cost-model/src/transaction_cost.rs

@@ -5,9 +5,8 @@ use {crate::block_cost_limits, solana_sdk::pubkey::Pubkey};
 /// Resources required to process a regular transaction often include
 /// an array of variables, such as execution cost, loaded bytes, write
 /// lock and read lock etc.
-/// Vote has a simple and pre-determined format, therefore can have
-/// a constant cost, skipping transaction inspection as required for
-/// non-vote transaction.
+/// Vote has a simpler and pre-determined format, it's cost structure
+/// can be simpler, calculation quicker.
 #[derive(Debug)]
 pub enum TransactionCost {
     Vote { writable_accounts: Vec<Pubkey> },