Clean up logging (#3161)

- use `Err` method instead of format strings
- use `Msg` if no format string is used

server/grpc/auth_server.go

@@ -69,7 +69,7 @@ func (s *WoodpeckerAuthServer) getAgent(agentID int64, agentToken string) (*mode
 			agent.Capacity = -1
 			err := s.store.AgentCreate(agent)
 			if err != nil {
-				log.Err(err).Msgf("Error creating system agent: %s", err)
+				log.Error().Err(err).Msg("Error creating system agent")
 				return nil, err
 			}
 			return agent, nil

server/grpc/rpc.go

@@ -212,7 +212,7 @@ func (s *RPC) Init(c context.Context, id string, state rpc.State) error {
 			Pipeline: *currentPipeline,
 		})
 		if err != nil {
-			log.Error().Err(err).Msgf("could not marshal JSON")
+			log.Error().Err(err).Msg("could not marshal JSON")
 			return
 		}
 		s.pubsub.Publish(message)