We allocate memory base on hisi_hba->hw->complete_hdr_size for DQ, but
it was wrong.For the structure, which used to save DQ, is
struct hisi_sas_cmd_hdr, and this size is not saved at
variables: complete_hdr_size.

So we need to correct it.
Signed-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>

Feature or Bugfix:Bugfix
Signed-off-by: Nluojiaxing <luojiaxing@huawei.com>
Reviewed-by: Nchenxiang <chenxiang66@hisilicon.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>