RDMA/rtrs-clt: Rename __rtrs_clt_change_state to rtrs_clt_change_state

Let's rename it to rtrs_clt_change_state since the previous one is
killed.

Also update the comment to make it more clear.

Link: https://lore.kernel.org/r/20201217141915.56989-13-jinpu.wang@cloud.ionos.com


Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>