mac80211: mesh: always use the latest target_sn

When a path target responds to a path request, its response
always contains the most up-to-date information; accordingly,
it should use the latest target_sn, regardless of
net_traversal_jiffies().  Otherwise, only the first path
response is considered when constructing a path, as it will
have the highest target_sn of all replies during that period.
Signed-off-by: Bob Copeland <bob@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mesh_hwmp.c

@@ -544,9 +544,10 @@ static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
 		if (time_after(jiffies, ifmsh->last_sn_update +
 					net_traversal_jiffies(sdata)) ||
 		    time_before(jiffies, ifmsh->last_sn_update)) {
-			target_sn = ++ifmsh->sn;
+			++ifmsh->sn;
 			ifmsh->last_sn_update = jiffies;
 		}
+		target_sn = ifmsh->sn;
 	} else if (is_broadcast_ether_addr(target_addr) &&
 		   (target_flags & IEEE80211_PREQ_TO_FLAG)) {
 		rcu_read_lock();