net/mlx4: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1].

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: GustavoARSilva

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -806,10 +806,10 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 				goto xdp_drop_no_cnt; /* Drop on xmit failure */
 			default:
 				bpf_warn_invalid_xdp_action(act);
-				/* fall through */
+				fallthrough;
 			case XDP_ABORTED:
 				trace_xdp_exception(dev, xdp_prog, act);
-				/* fall through */
+				fallthrough;
 			case XDP_DROP:
 				ring->xdp_drop++;
 xdp_drop_no_cnt:

drivers/net/ethernet/mellanox/mlx4/eq.c

@@ -558,7 +558,7 @@ static int mlx4_eq_int(struct mlx4_dev *dev, struct mlx4_eq *eq)
 			mlx4_dbg(dev, "%s: MLX4_EVENT_TYPE_SRQ_LIMIT. srq_no=0x%x, eq 0x%x\n",
 				 __func__, be32_to_cpu(eqe->event.srq.srqn),
 				 eq->eqn);
-			/* fall through */
+			fallthrough;
 		case MLX4_EVENT_TYPE_SRQ_CATAS_ERROR:
 			if (mlx4_is_master(dev)) {
 				/* forward only to slave owning the SRQ */

drivers/net/ethernet/mellanox/mlx4/mcg.c

@@ -1412,7 +1412,7 @@ int mlx4_multicast_attach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
 	case MLX4_STEERING_MODE_A0:
 		if (prot == MLX4_PROT_ETH)
 			return 0;
-		/* fall through */
+		fallthrough;
 
 	case MLX4_STEERING_MODE_B0:
 		if (prot == MLX4_PROT_ETH)
@@ -1442,7 +1442,7 @@ int mlx4_multicast_detach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
 	case MLX4_STEERING_MODE_A0:
 		if (prot == MLX4_PROT_ETH)
 			return 0;
-		/* fall through */
+		fallthrough;
 
 	case MLX4_STEERING_MODE_B0:
 		if (prot == MLX4_PROT_ETH)