dm: fix REQ_OP_ZONE_REPORT bio handling

A REQ_OP_ZONE_REPORT bio is not a medium access command.  Its number of
sectors indicates the maximum size allowed for the report reply size and
not an amount of sectors accessed from the device.  REQ_OP_ZONE_REPORT
bios should thus not be split depending on the target device maximum I/O
length but passed as-is.  Note that it is the responsability of the
target to remap and format the report reply.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>