IB/srpt: Remove WARN_ON from srpt_cm_req_recv

The callers pass the pointer '&req' or 'private_data' to
srpt_cm_req_recv(), and 'private_data' is initialized in srp_send_req().
'sdev' is allocated and stored in srpt_add_one(). It's easy to show that
sdev and req are always valid. So we remove unnecessary WARN_ON.

Link: https://lore.kernel.org/r/20200617140803.181333-1-jingxiangfeng@huawei.com
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -2156,9 +2156,6 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
 
 	WARN_ON_ONCE(irqs_disabled());
 
-	if (WARN_ON(!sdev || !req))
-		return -EINVAL;
-
 	it_iu_len = be32_to_cpu(req->req_it_iu_len);
 
 	pr_info("Received SRP_LOGIN_REQ with i_port_id %pI6, t_port_id %pI6 and it_iu_len %d on port %d (guid=%pI6); pkey %#04x\n",