RDMA/rtrs: Update comments for MAX_SESS_QUEUE_DEPTH

The maximum queue_depth should be 65535 per check_module_params,
also update other relevant comments.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20220902101922.26273-2-guoqing.jiang@linux.dev


Signed-off-by: Leon Romanovsky <leon@kernel.org>