block/vmdk: Improve error messages on extent write error

vmdk_init_extent() reports blk_co_pwrite() failure to its caller as

    An IO error has occurred

The errno code returned by blk_co_pwrite() is lost.

Improve this to

    failed to write VMDK <what>: <description of errno>

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240513141703.549874-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
1 file changed