fix file util

Signed-off-by: 梦境迷离 <dreamylost@outlook.com>

smt-csv/src/main/scala/org/bitlap/csv/FileUtils.scala

@@ -59,6 +59,7 @@ object FileUtils {
           } else {
             r.println(line)
           }
+          r.flush()
         }
       }
     finally bufferedWriter.close()