[help] confirming ostest output in KERNEL mode

Thanks for making `ostest` loadable in KERNEL mode NuttX!

I run it with kernel build on CanMV230 and got the following dumps at the end:

```
Final memory usage:
VARIABLE BEFORE AFTER
======== ======== ========
arena 80ff8 80ff8
ordblks 2 4
mxordblk 7cff0 787f0
uordblks 2658 3598
fordblks 7e9a0 7da60
user_main: Exiting
ostest_main: Exiting with status -1
```

Is this expected? I understand that test cases might be different from FLAT build, but not sure on the exit code.