xfrm: wrong hash value for temporary SA

When kernel inserts a temporary SA for IKE, it uses the wrong hash
value for dst list. Two hash values were calcultated before: one with
source address and one with a wildcard source address.

Bug hinted by Junwei Zhang <junwei.zhang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>