block: refactor disk_zone_wplug_sync_wp_offset()

block: refactor disk_zone_wplug_sync_wp_offset()

The helper function blk_zone_wp_offset() is called from
disk_zone_wplug_sync_wp_offset(), and again called from
blk_revalidate_seq_zone() right after the call to
disk_zone_wplug_sync_wp_offset().

Change disk_zone_wplug_sync_wp_offset() to return the value of obtained
with blk_zone_wp_offset() to avoid this double call, which simplifies a
little blk_revalidate_seq_zone().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>