xfrm: Use the user specified truncation length in ESP and AH

Instead of using the hardcoded truncation for authentication
algorithms, use the truncation length specified on xfrm_state.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 0f526f8..c2f300c 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -667,7 +667,7 @@
 	}
 
 	ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
-	ahp->icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
+	ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
 
 	BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);