mac80211: mesh: fix missing unlock on error in table_path_del()

spin_lock_bh() is used in table_path_del() but rcu_read_unlock()
is used for unlocking. Fix it by using spin_unlock_bh() instead
of rcu_read_unlock() in the error handling case.

Fixes: b4c3fbe6 ("mac80211: Use linked list instead of rhashtable walk for mesh tables")
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/mesh_pathtbl.c

@@ -627,7 +627,7 @@ static int table_path_del(struct mesh_table *tbl,
 	spin_lock_bh(&tbl->walk_lock);
 	mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
 	if (!mpath) {
-		rcu_read_unlock();
+		spin_unlock_bh(&tbl->walk_lock);
 		return -ENXIO;
 	}