block/rnbd-clt: Change queue_depth type in rnbd_clt_session to size_t

The member queue_depth in the structure rnbd_clt_session is read from the
rtrs client side using the function rtrs_clt_query, which in turn is read
from the rtrs_clt structure. It should really be of type size_t.

Fixes: 90426e89

 ("block/rnbd: client: private header with client structs and functions")
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Link: https://lore.kernel.org/r/20210428061359.206794-2-gi-oh.kim@ionos.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>