IB/hns: Fix for removal of redundant code

This patch removes the redundant code lines present in the
functions get_send_wqe() and get_recv_wqe(). This also fixes
the error in calculating the SQ WQE.

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Reviewed-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>