RDMA/siw: Balance the reference of cep->kref in the error path

The siw_connect can go to err in below after cep is allocated successfully:

1. If siw_cm_alloc_work returns failure. In this case socket is not
assoicated with cep so siw_cep_put can't be called by siw_socket_disassoc.
We need to call siw_cep_put twice since cep->kref is increased once after
it was initialized.

2. If siw_cm_queue_work can't find a work, which means siw_cep_get is not
called in siw_cm_queue_work, so cep->kref is increased twice by siw_cep_get
and when associate socket with cep after it was initialized. So we need to
call siw_cep_put three times (one in siw_socket_disassoc).

3. siw_send_mpareqrep returns error, this scenario is similar as 2.

So we need to remove one siw_cep_put in the error path.

Fixes: 6c52fdc ("rdma/siw: connection management")
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20230821133255.31111-2-guoqing.jiang@linux.dev
Acked-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Guoqing Jiang

drivers/infiniband/sw/siw/siw_cm.c

@@ -1501,7 +1501,6 @@ int siw_connect(struct iw_cm_id *id, struct iw_cm_conn_param *params)
 
 		cep->cm_id = NULL;
 		id->rem_ref(id);
-		siw_cep_put(cep);
 
 		qp->cep = NULL;
 		siw_cep_put(cep);