RDMA/mlx5: Delete struct mlx5_priv->mkey_table

No users are left, delete it.

Link: https://lore.kernel.org/r/20191009160934.3143-5-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mr.c

@@ -90,8 +90,6 @@ static void reg_mr_callback(int status, struct mlx5_async_work *context)
 	struct mlx5_cache_ent *ent = &cache->ent[c];
 	u8 key;
 	unsigned long flags;
-	struct xarray *mkeys = &dev->mdev->priv.mkey_table;
-	int err;
 
 	spin_lock_irqsave(&ent->lock, flags);
 	ent->pending--;
@@ -118,13 +116,6 @@ static void reg_mr_callback(int status, struct mlx5_async_work *context)
 	ent->size++;
 	spin_unlock_irqrestore(&ent->lock, flags);
 
-	xa_lock_irqsave(mkeys, flags);
-	err = xa_err(__xa_store(mkeys, mlx5_base_mkey(mr->mmkey.key),
-				&mr->mmkey, GFP_ATOMIC));
-	xa_unlock_irqrestore(mkeys, flags);
-	if (err)
-		pr_err("Error inserting to mkey tree. 0x%x\n", -err);
-
 	if (!completion_done(&ent->compl))
 		complete(&ent->compl);
 }