docs: modify max_open_zones option description

docs: modify max_open_zones option description

A recent commit modified the max_open_zones option to improve handling
of zoned block devices with max_active_zones limit. Modify description
of the option to meet the change.

For that purpose, explain the relation between the max_open_zones option
and the device side limits max_active_zones and max_open_zones. Also
mention about three zone conditions 'implicit open', 'explict open' and
'closed'. And replace the word 'zone state' with 'zone condition'.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230719105756.553146-5-shinichiro.kawasaki@wdc.com
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>