ipv6: fix error propagation in ip6_ufo_append_data()

We should return errcode from sock_alloc_send_skb()

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index ff30047..84d0bd5 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1123,7 +1123,7 @@
 			hh_len + fragheaderlen + transhdrlen + 20,
 			(flags & MSG_DONTWAIT), &err);
 		if (skb == NULL)
-			return -ENOMEM;
+			return err;
 
 		/* reserve space for Hardware header */
 		skb_reserve(skb, hh_len);