[RFC] closeout redundant diagnostic

[Pádraig Brady]

I was just testing a framebuffer device here and
noticed that there were 2 errors printed by `tr`

$ tr '\0' $(($RANDOM % 256)) </dev/zero >/dev/full
tr: write error: No space left on device
tr: write error

I was then wondering it there was some other
error with the device rather than just filling it.
But the latter error is just closeout() noticing
the original write error, and diagnosing just
in case the original writer did not.

So 3 options.

1. leave as is
2. assume all writers will diagnose,
so don't diagnose previous errors in closeout()
3. make it configurable (with close_stdout_set_ignore_previous())

I might just leave as is?

cheers,
Pádraig.