net: convert BUG_TRAP to generic WARN_ON

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 08392ed..df2f110 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -413,7 +413,7 @@
 
 		/* Stop the REQUEST timer */
 		inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
-		BUG_TRAP(sk->sk_send_head != NULL);
+		WARN_ON(sk->sk_send_head == NULL);
 		__kfree_skb(sk->sk_send_head);
 		sk->sk_send_head = NULL;