Improve error string and remove unneeded else clause

rpc/api/eth.go

@@ -565,7 +565,7 @@ func (self *ethApi) GetWork(req *shared.Request) (interface{}, error) {
 	self.xeth.SetMining(true, 0)
 	ret, err := self.xeth.RemoteMining().GetWork()
 	if err != nil {
-		return nil, shared.NewNotReadyError("getWork")
+		return nil, shared.NewNotReadyError("mining work")
 	} else {
 		return ret, nil
 	}

rpc/shared/errors.go

@@ -65,16 +65,16 @@ func NewNotImplementedError(method string) *NotImplementedError {
 }
 
 type NotReadyError struct {
-	Method string
+	Resource string
 }
 
 func (e *NotReadyError) Error() string {
-	return fmt.Sprintf("%s method not ready", e.Method)
+	return fmt.Sprintf("%s not ready", e.Resource)
 }
 
-func NewNotReadyError(method string) *NotReadyError {
+func NewNotReadyError(resource string) *NotReadyError {
 	return &NotReadyError{
-		Method: method,
+		Resource: resource,
 	}
 }