memory allocated by kmem_cache_alloc() should be freed using
kmem_cache_free(), not kfree().
Fixes: ea3c88b53a85 ('openvswitch: Per cpu flow stats.') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>