xfrm: call xfrm_dev_state_delete when xfrm_state_migrate fails to add the state

xfrm: call xfrm_dev_state_delete when xfrm_state_migrate fails to add the state

In case xfrm_state_migrate fails after calling xfrm_dev_state_add, we
directly release the last reference and destroy the new state, without
calling xfrm_dev_state_delete (this only happens in
__xfrm_state_delete, which we're not calling on this path, since the
state was never added).

Call xfrm_dev_state_delete on error when an offload configuration was
provided.

Fixes: ab244a394c7f ("xfrm: Migrate offload configuration")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>