ipv6: remove unnecessary check in addrconf_prefix_rcv_add_addr()

Remove unnecessary check on update_lft variable in
addrconf_prefix_rcv_add_addr routine since it is always set to 0.
Moreover remove update_lft re-initialization to 0
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -2529,7 +2529,6 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
 		if (IS_ERR_OR_NULL(ifp))
 			return -1;
 
-		update_lft = 0;
 		create = 1;
 		spin_lock_bh(&ifp->lock);
 		ifp->flags |= IFA_F_MANAGETEMPADDR;
@@ -2551,7 +2550,7 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
 			stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
 		else
 			stored_lft = 0;
-		if (!update_lft && !create && stored_lft) {
+		if (!create && stored_lft) {
 			const u32 minimum_lft = min_t(u32,
 				stored_lft, MIN_VALID_LIFETIME);
 			valid_lft = max(valid_lft, minimum_lft);