net/mlx5e: Set of completion request bit should not clear other adjacent bits

In notify HW (ring doorbell) flow, we set the bit to request a completion
on the TX descriptor.
When doing so, we should not unset other bits in the same byte.
Currently, this does not fix a real issue, as we still don't have a flow
where both MLX5_WQE_CTRL_CQ_UPDATE and any adjacent bit are set together.

Fixes: 542578c6 ("net/mlx5e: Move helper functions to a new txrx datapath header")
Fixes: 864b2d71 ("net/mlx5e: Generalize tx helper functions for different SQ types")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h

@@ -102,7 +102,7 @@ static inline void
 mlx5e_notify_hw(struct mlx5_wq_cyc *wq, u16 pc, void __iomem *uar_map,
 		struct mlx5_wqe_ctrl_seg *ctrl)
 {
-	ctrl->fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
+	ctrl->fm_ce_se |= MLX5_WQE_CTRL_CQ_UPDATE;
 	/* ensure wqe is visible to device before updating doorbell record */
 	dma_wmb();