RDMA/nes: Cosmetic changes

 - Remove unnecessary statement "if (1)"
 - Refactor a statement (wqe_misc |= NES_NIC_SQ_WQE_COMPLETION) out of
   if/else statement, because it is independant of the flow.
 - Define netdev->features in one line for clarity.

Signed-off-by: Tatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>