simplify passthrough bio handling

[Christoph Hellwig]

Hi Jens,

this series removes the special casing when adding pages to passthrough
bios in favor of simply checking that they match the queue limits once
before submissions.  This mirrors where the zone append users have been
moving and a recent doing the same for a single optimizes passthrough
user.

Diffstat:
 block/bio.c                        |  107 +-----------------------------
 block/blk-map.c                    |  128 ++++++++++---------------------------
 block/blk-mq.c                     |    4 -
 block/blk.h                        |    8 --
 drivers/nvme/target/passthru.c     |   18 +++--
 drivers/nvme/target/zns.c          |    3 
 drivers/target/target_core_pscsi.c |    6 -
 include/linux/bio.h                |    2 
 include/linux/blk-mq.h             |    8 --
 9 files changed, 57 insertions(+), 227 deletions(-)