[IPSEC]: Fix inter address family IPsec tunnel handling.

Signed-off-by: Kazunori MIYAZAWA <kazunori@miyazawa.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 8b5f486..e9ef9af 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1219,7 +1219,7 @@
 		x->sel.prefixlen_s = addr->sadb_address_prefixlen;
 	}
 
-	if (!x->sel.family)
+	if (x->props.mode == XFRM_MODE_TRANSPORT)
 		x->sel.family = x->props.family;
 
 	if (ext_hdrs[SADB_X_EXT_NAT_T_TYPE-1]) {