bridge: fix a typo in comments

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_multicast.c

@@ -1012,7 +1012,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
 #endif
 
 /*
- * Add port to rotuer_list
+ * Add port to router_list
  *  list is maintained ordered by pointer value
  *  and locked by br->multicast_lock and RCU
  */