net/mlx4_core: Fix memory access error in mlx4_QUERY_DEV_CAP_wrapper()

Fix a regression introduced by [1]. outbox was accessed instead of
outbox->buf. Typo was copy-pasted to [2] and [3].

[1] - cc1ade9 mlx4_core: Disable memory windows for virtual functions
[2] - 4de65803 mlx4_core: Add support for steerable IB UD QPs
[3] - 7ffdf726 net/mlx4_core: Add basic support for TCP/IP offloads under
      tunneling
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -859,7 +859,7 @@ int mlx4_QUERY_DEV_CAP_wrapper(struct mlx4_dev *dev, int slave,
 	MLX4_PUT(outbox->buf, field, QUERY_DEV_CAP_CQ_TS_SUPPORT_OFFSET);
 
 	/* For guests, disable vxlan tunneling */
-	MLX4_GET(field, outbox, QUERY_DEV_CAP_VXLAN);
+	MLX4_GET(field, outbox->buf, QUERY_DEV_CAP_VXLAN);
 	field &= 0xf7;
 	MLX4_PUT(outbox->buf, field, QUERY_DEV_CAP_VXLAN);
 
@@ -869,7 +869,7 @@ int mlx4_QUERY_DEV_CAP_wrapper(struct mlx4_dev *dev, int slave,
 	MLX4_PUT(outbox->buf, field, QUERY_DEV_CAP_BF_OFFSET);
 
 	/* For guests, disable mw type 2 */
-	MLX4_GET(bmme_flags, outbox, QUERY_DEV_CAP_BMME_FLAGS_OFFSET);
+	MLX4_GET(bmme_flags, outbox->buf, QUERY_DEV_CAP_BMME_FLAGS_OFFSET);
 	bmme_flags &= ~MLX4_BMME_FLAG_TYPE_2_WIN;
 	MLX4_PUT(outbox->buf, bmme_flags, QUERY_DEV_CAP_BMME_FLAGS_OFFSET);
 
@@ -883,7 +883,7 @@ int mlx4_QUERY_DEV_CAP_wrapper(struct mlx4_dev *dev, int slave,
 	}
 
 	/* turn off ipoib managed steering for guests */
-	MLX4_GET(field, outbox, QUERY_DEV_CAP_FLOW_STEERING_IPOIB_OFFSET);
+	MLX4_GET(field, outbox->buf, QUERY_DEV_CAP_FLOW_STEERING_IPOIB_OFFSET);
 	field &= ~0x80;
 	MLX4_PUT(outbox->buf, field, QUERY_DEV_CAP_FLOW_STEERING_IPOIB_OFFSET);