Fix golangci-lint issues

As part of updating dapper files, golangci-lint was set to be used. This
caused a lot of lint issues to crop up, which this fixes.

pkg/subscribe/handler.go

@@ -85,7 +85,7 @@ func handler(apiContext *types.APIContext) error {
 	}
 
 	go func() {
-		readerGroup.Wait()
+		_ = readerGroup.Wait()
 		close(events)
 	}()