netfilter: remove double colon

This is C not shell script

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index c3e0ade..7ebd6e3 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -61,7 +61,7 @@
 		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