xfrm: add missed call to delete offloaded policies

Offloaded policies are deleted through two flows: netdev is going
down and policy flush.

In both cases, the code lacks relevant call to delete offloaded policy.

Fixes: 919e43fa ("xfrm: add an interface to offload policy")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/xfrm/xfrm_policy.c

@@ -1831,6 +1831,7 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 
 		__xfrm_policy_unlink(pol, dir);
 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
+		xfrm_dev_policy_delete(pol);
 		cnt++;
 		xfrm_audit_policy_delete(pol, 1, task_valid);
 		xfrm_policy_kill(pol);
@@ -1869,6 +1870,7 @@ int xfrm_dev_policy_flush(struct net *net, struct net_device *dev,
 
 		__xfrm_policy_unlink(pol, dir);
 		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
+		xfrm_dev_policy_delete(pol);
 		cnt++;
 		xfrm_audit_policy_delete(pol, 1, task_valid);
 		xfrm_policy_kill(pol);