Remove legacy balance query (ethereum#244)

* Add legacy balance query

* remove legacy bals

* remove legacy check

* update balance check

core/state/statedb.go

@@ -25,7 +25,6 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/diffdb"
@@ -268,21 +267,14 @@ func (s *StateDB) GetBalance(addr common.Address) *big.Int {
 
 func (s *StateDB) GetOVMBalance(addr common.Address) *big.Int {
 	eth := common.HexToAddress("0x4200000000000000000000000000000000000006")
-	position1 := big.NewInt(3)
-	hasher1 := sha3.NewLegacyKeccak256()
-	hasher1.Write(common.LeftPadBytes(addr.Bytes(), 32))
-	hasher1.Write(common.LeftPadBytes(position1.Bytes(), 32))
-	digest1 := hasher1.Sum(nil)
-	key1 := common.BytesToHash(digest1)
-	slot1 := s.GetState(eth, key1)
-	position2 := big.NewInt(5)
-	hasher2 := sha3.NewLegacyKeccak256()
-	hasher2.Write(common.LeftPadBytes(addr.Bytes(), 32))
-	hasher2.Write(common.LeftPadBytes(position2.Bytes(), 32))
-	digest := hasher2.Sum(nil)
-	key2 := common.BytesToHash(digest)
-	slot2 := s.GetState(eth, key2)
-	return math.BigMax(slot1.Big(), slot2.Big())
+	position := big.NewInt(5)
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write(common.LeftPadBytes(addr.Bytes(), 32))
+	hasher.Write(common.LeftPadBytes(position.Bytes(), 32))
+	digest := hasher.Sum(nil)
+	key := common.BytesToHash(digest)
+	slot := s.GetState(eth, key)
+	return slot.Big()
 }
 
 func (s *StateDB) GetNonce(addr common.Address) uint64 {