net/mlx5e: IPsec: Use kvfree() for memory allocated with kvzalloc()

Variables flow_group_in, spec in rx_fs_create() are allocated with
kvzalloc(). It's incorrect to free them with kfree(). Use kvfree()
instead.

Fixes: 5e466345

 ("net/mlx5e: IPsec: Add IPsec steering in local NIC RX")
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>