fix typo

plugins/inputs/oceanbase/log/error_log_input.go

@@ -84,7 +84,7 @@ type ErrorLogInput struct {
 	logProcessQueue         map[ServiceType]*processQueue
 	ctx                     context.Context
 	cancel                  context.CancelFunc
-	tbackgroundTaskWaitGroup sync.WaitGroup
+	backgroundTaskWaitGroup sync.WaitGroup
 	metricBufferChan        chan []metric.Metric
 }