netfilter: nf_nat: remove obsolete rcu_read_unlock call

hlist walk in find_appropriate_src() is not protected anymore by rcu_read_lock(),
so rcu_read_unlock() is unnecessary if in_range() matches.

This bug was added in (c7232c99 netfilter: add protocol independent NAT core).
Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_nat_core.c

@@ -201,10 +201,8 @@ find_appropriate_src(struct net *net, u16 zone,
 				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 			result->dst = tuple->dst;
 
-			if (in_range(l3proto, l4proto, result, range)) {
-				rcu_read_unlock();
+			if (in_range(l3proto, l4proto, result, range))
 				return 1;
-			}
 		}
 	}
 	return 0;