RDMA/rtrs-srv: Kill __rtrs_srv_change_state

No need since the only user is rtrs_srv_change_state.

Link: https://lore.kernel.org/r/20210528113018.52290-11-jinpu.wang@ionos.com


Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>