Revert "RDMA/mlx5: Fix releasing unallocated memory in dereg MR flow"

This patch is not the full fix and still causes to call traces
during mlx5_ib_dereg_mr().

This reverts commit f0ae4afe.

Fixes: f0ae4afe

 ("RDMA/mlx5: Fix releasing unallocated memory in dereg MR flow")
Link: https://lore.kernel.org/r/20211222101312.1358616-1-maorg@nvidia.com
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Acked-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>