create_win_dump() and write_run report qemu_write_full() failure to
their callers as
An IO error has occurred
The errno set by qemu_write_full() is lost.
Improve this to
win-dump: failed to write header: <description of errno>
and
win-dump: failed to save memory: <description of errno>
This matches how dump.c reports similar errors.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240513141703.549874-3-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>