xfrm: Fix truncation length of authentication algorithms installed via PF_KEY

Commit 4447bb33 ("xfrm: Store aalg in
xfrm_state with a user specified truncation length") breaks
installation of authentication algorithms via PF_KEY, as the state
specific truncation length is not installed with the algorithms
default truncation length.  This patch initializes state properly to
the default if installed via PF_KEY.
Signed-off-by: NMartin Willi <martin@strongswan.org>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/key/af_key.c

@@ -1193,6 +1193,7 @@ static struct xfrm_state * pfkey_msg2xfrm_state(struct net *net,
 			x->aalg->alg_key_len = key->sadb_key_bits;
 			memcpy(x->aalg->alg_key, key+1, keysize);
 		}
+		x->aalg->alg_trunc_len = a->uinfo.auth.icv_truncbits;
 		x->props.aalgo = sa->sadb_sa_auth;
 		/* x->algo.flags = sa->sadb_sa_flags; */
 	}