all: next batch of log polishes to contextual versions

core/state_transition.go

@@ -18,7 +18,6 @@ package core
 
 import (
 	"errors"
-	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -256,7 +255,7 @@ func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *b
 		ret, self.gas, vmerr = evm.Call(sender, self.to().Address(), self.data, self.gas, self.value)
 	}
 	if vmerr != nil {
-		log.Debug(fmt.Sprint("vm returned with error:", err))
+		log.Debug("VM returned with error", "err", err)
 		// The only possible consensus-error would be if there wasn't
 		// sufficient balance to make the transfer happen. The first
 		// balance transfer may never fail.