The process of flushing CQE can be encapsultated into a function, which
can reduce duplicate code.

Link: https://lore.kernel.org/r/1624011020-16992-9-git-send-email-liweihang@huawei.comSigned-off-by: NWenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>