net/mlx5e: nullify cq->dbg pointer in mlx5_debug_cq_remove()

net/mlx5e: nullify cq->dbg pointer in mlx5_debug_cq_remove()

This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven.
This ID is fixed in Linux Kernel version v5.15.5 by commit 2ae38157080616a13a9fe3f0b4b6ec0070aa408a, it was introduced in version v5.15 by commit 94b960b9deffc02fc0747afc01f72cc62ab099e3. For more details please see the references link.