ipv6: fix the comment of ip6_xmit()

ip6_xmit() is used by upper transport protocol.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.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 141819f..5129a16 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -181,7 +181,7 @@
 }
 
 /*
- *	xmit an sk_buff (used by TCP)
+ *	xmit an sk_buff (used by TCP, SCTP and DCCP)
  */
 
 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,