net/mlx5e: MACsec, fix add Rx security association (SA) rule memory leak

Currently MACsec's add Rx SA flow steering (fs) rule routine
uses a spec object which is dynamically allocated and do
not free it upon leaving. The above led to a memory leak.

Fix by freeing dynamically allocated objects.

Fixes: 3b20949c ("net/mlx5e: Add MACsec RX steering rules")
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec_fs.c

@@ -1209,6 +1209,7 @@ macsec_fs_rx_add_rule(struct mlx5e_macsec_fs *macsec_fs,
 		rx_rule->rule[1] = rule;
 	}
 
+	kvfree(spec);
 	return macsec_rule;
 
 err: