netfilter: remove double colon

This is C not shell script

Signed-off-by: Stephen Hemminger <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/ipv4/netfilter.c

···
 		skb_dst_set(skb, NULL);
 		dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), skb->sk, 0);
 		if (IS_ERR(dst))
-			return PTR_ERR(dst);;
+			return PTR_ERR(dst);
 		skb_dst_set(skb, dst);
 	}
 #endif