RDMA/hns: Fix undifined behavior caused by invalid max_sge

If max_sge has been set to 0, roundup_pow_of_two() in
set_srq_basic_param() may have undefined behavior.

Fixes: 9dd05247 ("RDMA/hns: Allocate one more recv SGE for HIP08")
Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240710133705.896445-7-huangjunxian6@hisilicon.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>