net/mlx5: use kvfree() for kvzalloc() in mlx5_ct_fs_smfs_matcher_create

The memory of spec is allocated with kvzalloc(), the corresponding
release function should not be kfree(), use kvfree() instead.

Generated by: scripts/coccinelle/api/kfree_mismatch.cocci

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>