RDMA/rtrs-clt: Kill rtrs_clt_disconnect_from_sysfs

The function is just a wrapper of rtrs_clt_close_conns, let's call
rtrs_clt_close_conns directly.

Link: https://lore.kernel.org/r/20210528113018.52290-10-jinpu.wang@ionos.com


Signed-off-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>