[server] set serial port fd back to blocking if necessary

[Alexandre Julliard]

"Damjan Jovanovic" <damjan.jov at gmail.com> writes:

> This fixes a regression caused by commit
> f85437c57fb44d511db97edbaa5b1f8abfe75fd3 (bug 9356) where serial ports
> break because they are not made blocking.
>
> Changelog:
> * Set serial port fd back to blocking if necessary

This will break timeout handling. There shouldn't be any reason for the
fd to be blocking, we should handle EAGAIN properly.

-- 
Alexandre Julliard
julliard at winehq.org