remove leftovers of the old ->media_changed method

[Christoph Hellwig]

Hi Jens,

this series converts md as the last user of the ->media_changed method
over to the modern replacement, and then cleans up a few lose ends in
the area.

Diffstat:
 Documentation/cdrom/cdrom-standard.rst |   18 +-----------------
 Documentation/filesystems/locking.rst  |    4 +---
 arch/xtensa/platforms/iss/simdisk.c    |    2 --
 block/genhd.c                          |    7 +------
 drivers/cdrom/cdrom.c                  |   28 +++++-----------------------
 drivers/md/md.c                        |   19 ++++++++-----------
 drivers/mmc/core/block.c               |    3 ---
 fs/block_dev.c                         |   30 +++++++-----------------------
 fs/isofs/inode.c                       |    3 ---
 include/linux/blkdev.h                 |    2 --
 include/linux/cdrom.h                  |    2 --
 11 files changed, 23 insertions(+), 95 deletions(-)