net/mlx5e: Fix use-after-free race in sample_restore_put()

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free race in sample_restore_put() Concurrent teardown of TC sample rules sharing the same restore context may re-read restore->count after dropping restore_lock. At that point another thread may already have completed cleanup and freed the restore object. Use the result of the refcount decrement while holding restore_lock to determine whether cleanup is needed.

Where it's fixed