miner: fix txFitsSize comment (#34100)

Rename the comment so it matches the helper name.

miner/worker.go

@@ -75,7 +75,7 @@ type environment struct {
 	witness *stateless.Witness
 }
 
-// txFits reports whether the transaction fits into the block size limit.
+// txFitsSize reports whether the transaction fits into the block size limit.
 func (env *environment) txFitsSize(tx *types.Transaction) bool {
 	return env.size+tx.Size() < params.MaxBlockSize-maxBlockSizeBufferZone
 }