UL does not report anything if disk writing fails

If there are no disk space enough to write UL, it does not report. So the user cannot know lack of logs timely.

`LogFileStreamOutput::write()` uses `jio_fprintf()` and `fflush()` to write log. However return values of them would not be checked.
We should check them, and should report what happened if error occurred.


How to reproduce on Linux:

1. Mount tmpfs with 512K

```
$ mkdir /tmp/tmp
$ mount -t tmpfs -o size=512k tmpfs /tmp/tmp
```

2. Run `java` with `-Xlog`

```
$ java -Xlog:all=trace:file=/tmp/tmp/all.log --version
```