RDMA/hns: Prevent memory leaks of eq->buf_list

eq->buf_list->buf and eq->buf_list should also be freed when eqe_hop_num
is set to 0, or there will be memory leaks.

Fixes: a5073d60 ("RDMA/hns: Add eq support of hip08")
Link: https://lore.kernel.org/r/1572072995-11277-3-git-send-email-liweihang@hisilicon.com


Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Weihang Li <liweihang@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>