xfrm: Remove rebundant address family checking

present_and_same_family has checked addresses family validness for both
SADB_EXT_ADDRESS_SRC and SADB_EXT_ADDRESS_DST in the beginning.
Thereafter pfkey_sadb_addr2xfrm_addr doesn't need to do the checking again.
Signed-off-by: NFan Du <fan.du@windriver.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

net/key/af_key.c

@@ -1196,10 +1196,6 @@ static struct xfrm_state * pfkey_msg2xfrm_state(struct net *net,
 
 	x->props.family = pfkey_sadb_addr2xfrm_addr((struct sadb_address *) ext_hdrs[SADB_EXT_ADDRESS_SRC-1],
 						    &x->props.saddr);
-	if (!x->props.family) {
-		err = -EAFNOSUPPORT;
-		goto out;
-	}
 	pfkey_sadb_addr2xfrm_addr((struct sadb_address *) ext_hdrs[SADB_EXT_ADDRESS_DST-1],
 				  &x->id.daddr);
 
@@ -2205,10 +2201,6 @@ static int pfkey_spdadd(struct sock *sk, struct sk_buff *skb, const struct sadb_
 
 	sa = ext_hdrs[SADB_EXT_ADDRESS_SRC-1];
 	xp->family = pfkey_sadb_addr2xfrm_addr(sa, &xp->selector.saddr);
-	if (!xp->family) {
-		err = -EINVAL;
-		goto out;
-	}
 	xp->selector.family = xp->family;
 	xp->selector.prefixlen_s = sa->sadb_address_prefixlen;
 	xp->selector.proto = pfkey_proto_to_xfrm(sa->sadb_address_proto);