Add one new array (marked with __maybe_unused to prevent gcc warning about
"defined but not used" with W=1), then we can remove rnbd_access_mode_str
and rnbd-common.c accordingly.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20230524070026.2932-4-guoqing.jiang@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

These are common private headers with rnbd protocol structures, logging,
sysfs and other helper functions, which are used on both client and server
sides.

Link: https://lore.kernel.org/r/20200511135131.27580-16-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>