Enable errcheck linter and resolve found issues.

Signed-off-by: Xun Jiang <blackpiglet@gmail.com>

pkg/plugin/framework/object_store_client.go

@@ -87,7 +87,9 @@ func (c *ObjectStoreGRPCClient) PutObject(bucket, key string, body io.Reader) er
 			return nil
 		}
 		if err != nil {
-			stream.CloseSend()
+			if err := stream.CloseSend(); err != nil {
+				return common.FromGRPCError(err)
+			}
 			return errors.WithStack(err)
 		}
 

pkg/plugin/framework/server.go

@@ -232,7 +232,10 @@ func getNames(command string, kind common.PluginKind, plugin Interface) []Plugin
 func (s *server) Serve() {
 	if s.flagSet != nil && !s.flagSet.Parsed() {
 		s.log.Debugf("Parsing flags")
-		s.flagSet.Parse(os.Args[1:])
+		if err := s.flagSet.Parse(os.Args[1:]); err != nil {
+			s.log.Errorf("fail to parse the flags: %s", err.Error())
+			return
+		}
 	}
 
 	s.log.Level = s.logLevelFlag.Parse()