get last os error when file access failed

[templexxx]

Always get bad address in present.

I don't think it's the right errno return by this call, because what I've changed is open flags, flags is just a integer(immediate number), no address releated to it.

[2022-11-04T12:39:10Z WARN  omo::os::linux] failed to open (lines.txt, 533249, 438): IOError(Os { code: 14, kind: Uncategorized, message: "Bad address" })

There maybe something wrong with the I/O error handler.

#30

[templexxx]

after get right syscall return, I found:

[2022-11-05T06:58:10Z DEBUG omo::os::linux] open(lines.txt, 533249, 438) pc: 4563320
[2022-11-05T06:58:10Z WARN  omo::os::linux] failed to open (lines.txt, 533249, 438): IOError(Os { code: 2, kind: NotFound, message: "No such file or directory" })

this flags: 533249 (0x82301) causes No such file or directory error #32

[templexxx]

final implementaion:

1. log with warn level if there is a syscall error
2. return host's errno directly to the emulator