mlx5: Fix incorrect wc pkey_index assignment for GSI messages

Since patch series "Demux IB CM requests in the rdma_cm module" the
P_Key index is taken from the work completion rather than the message
itself.

The HCA provides us with the message P_Key. In order to provide the
P_Key index, we need to look it up. Given that this is relevant only
for GSI messages (session establishments) which is less performance critical,
micro-optimize against the GSI (is_qp1) branch.

Fixes: 4c21b5bcef73 ("IB/cma: Add net_dev and private data checks to
RDMA CM")
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index a5fa0b9..bb8cda7 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -680,6 +680,11 @@
 	       MLX5_PERM_LOCAL_READ;
 }
 
+static inline int is_qp1(enum ib_qp_type qp_type)
+{
+	return qp_type == IB_QPT_GSI;
+}
+
 #define MLX5_MAX_UMR_SHIFT 16
 #define MLX5_MAX_UMR_PAGES (1 << MLX5_MAX_UMR_SHIFT)