vfio/mlx5: Fix an unwind issue in mlx5vf_add_migration_pages()

In the Linux kernel, the following vulnerability has been resolved: vfio/mlx5: Fix an unwind issue in mlx5vf_add_migration_pages() Fix an unwind issue in mlx5vf_add_migration_pages(). If a set of pages is allocated but fails to be added to the SG table, they need to be freed to prevent a memory leak. Any pages successfully added to the SG table will be freed as part of mlx5vf_free_data_buffer().