compress/mlx5: fix leak on QP setup failure

compress/mlx5: fix leak on QP setup failure

The QP setup function allocates buffer for its
opaque MR and register it into MR structure.

After buffer allocation and before MR registration,
it tries allocate MR Btree.
When the MR Btree allocation fails, the buffer was
not freed what caused a memory leak.

Allocate the MR Btree before buffer alloction.

Fixes: 0165bccdb45f ("compress/mlx5: add memory region management")
Cc: stable@dpdk.org
Signed-off-by: Michael Baum <michaelba@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>