xfrm4: Remove duplicate semicolon

3328715e6c1fc (xfrm4: Add IPsec protocol multiplexer) adds a
duplicate semicolon after the return-statement.

Although it has no negative impact, the second semicolon should be
removed.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/ipv4/xfrm4_protocol.c

@@ -124,7 +124,7 @@ static int xfrm4_ah_rcv(struct sk_buff *skb)
 
 	for_each_protocol_rcu(ah4_handlers, handler)
 		if ((ret = handler->handler(skb)) != -EINVAL)
-			return ret;;
+			return ret;
 
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);