replace defer with manual close. defer is not good since should be cl…

…osed before uploading

plugins/out_clp_s3/flush/flush.go

@@ -84,7 +84,6 @@ func ToS3(data unsafe.Pointer, length int, tag string, ctx *outctx.S3Context) (i
 		err = fmt.Errorf("error opening zstd writer: %w", err)
 		return output.FLB_RETRY, err
 	}
-	defer zstdWriter.Close()
 
 	// IR buffer using bytes.Buffer internally, so it will dynamically grow if undersized. Using
 	// FourByteEncoding as default encoding.
@@ -107,6 +106,11 @@ func ToS3(data unsafe.Pointer, length int, tag string, ctx *outctx.S3Context) (i
 		return output.FLB_RETRY, err
 	}
 
+	err = zstdWriter.Close()
+	if err != nil {
+		return output.FLB_RETRY, err
+	}
+
 	outputLocation, err := uploadToS3(
 		ctx.Config.S3Bucket,
 		ctx.Config.S3BucketPrefix,