block/file-posix: fix update_zones_wp() caller

When the zoned request fail, it needs to update only the wp of
the target zones for not disrupting the in-flight writes on
these other zones. The wp is updated successfully after the
request completes.

Fixed the callers with right offset and nr_zones.

Signed-off-by: Sam Li <faithilikerun@gmail.com>
Message-Id: <20230825040556.4217-1-faithilikerun@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[hreitz: Rebased and fixed comment spelling]
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>