[DCCP]: Introduce dccp_wait_for_ccid and use it in dccp_write_xmit

This is not quite what I think we should have long term but improves
performance for now, so lets use it till we get CCID3 working well,
then we can think about using sk_write_queue, perhaps using some ideas
from Juwen Lai's old stack for 2.4.20.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index cf93b01..9866dc1 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -985,7 +985,7 @@
 		ccid3_pr_debug("send_packet delay=%ld\n", delay);
 		delay /= -1000;
 		/* divide by -1000 is to convert to ms and get sign right */
-		rc = delay > 0 ? -EAGAIN : 0;
+		rc = delay > 0 ? delay : 0;
 		break;
 	default:
 		printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",