[FAB-3764] Fixes the comments in ledger interface

This CR fixes the misplaced comments for function NewTxSimulator()
in ledger interface

Change-Id: I08bf8573e28c3ef17b2a459e3ec0cb7796e46a5a
Signed-off-by: manish <manish.sethi@gmail.com>

core/ledger/ledger_interface.go

@@ -48,12 +48,11 @@ type PeerLedger interface {
 	GetBlockByHash(blockHash []byte) (*common.Block, error)
 	// GetBlockByTxID returns a block which contains a transaction
 	GetBlockByTxID(txID string) (*common.Block, error)
+	// GetTxValidationCodeByTxID returns reason code of transaction validation
+	GetTxValidationCodeByTxID(txID string) (peer.TxValidationCode, error)
 	// NewTxSimulator gives handle to a transaction simulator.
 	// A client can obtain more than one 'TxSimulator's for parallel execution.
 	// Any snapshoting/synchronization should be performed at the implementation level if required
-
-	// GetTxValidationCodeByTxID returns reason code of transaction validation
-	GetTxValidationCodeByTxID(txID string) (peer.TxValidationCode, error)
 	NewTxSimulator() (TxSimulator, error)
 	// NewQueryExecutor gives handle to a query executor.
 	// A client can obtain more than one 'QueryExecutor's for parallel execution.