mlx5: minor fixes (mainly avoidance of hidden casts)

There were many places where parameters which should be u8/u16 were
integer type.

Additionally, in 2 places, a check for a non-null pointer was added
before dereferencing the pointer (this is actually a bug fix).

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index a0e204f..386780f 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -461,7 +461,7 @@
 void mlx5_ib_cq_clean(struct mlx5_ib_cq *cq, u32 qpn, struct mlx5_ib_srq *srq);
 void mlx5_ib_free_srq_wqe(struct mlx5_ib_srq *srq, int wqe_index);
 int mlx5_MAD_IFC(struct mlx5_ib_dev *dev, int ignore_mkey, int ignore_bkey,
-		 int port, struct ib_wc *in_wc, struct ib_grh *in_grh,
+		 u8 port, struct ib_wc *in_wc, struct ib_grh *in_grh,
 		 void *in_mad, void *response_mad);
 struct ib_ah *create_ib_ah(struct ib_ah_attr *ah_attr,
 			   struct mlx5_ib_ah *ah);