When 'kvzalloc()' is used to allocate memory, 'kvfree()' must be used to
free it.

Fixes: 1cbe6fc8 ("IB/mlx5: Add support for CQE compressing")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>